10710010@unknown@formal@none@1@S@
Predictive analytics
@@@@1@2@@danf@17-8-2009 10710020@unknown@formal@none@1@S@'''Predictive analytics''' encompasses a variety of techniques from [[statistics]] and [[data mining]] that analyze current and historical data to make predictions about future events.@@@@1@24@@danf@17-8-2009 10710030@unknown@formal@none@1@S@Such predictions rarely take the form of absolute statements, and are more likely to be expressed as values that correspond to the odds of a particular event or behavior taking place in the future.@@@@1@34@@danf@17-8-2009 10710040@unknown@formal@none@1@S@In business, predictive models exploit patterns found in historical and transactional data to identify risks and opportunities.@@@@1@17@@danf@17-8-2009 10710050@unknown@formal@none@1@S@Models capture relationships among many factors to allow assessment of risk or potential associated with a particular set of conditions, guiding decision making for candidate transactions.@@@@1@26@@danf@17-8-2009 10710060@unknown@formal@none@1@S@One of the most well-known applications is [[credit scoring]], which is used throughout [[financial services]].@@@@1@15@@danf@17-8-2009 10710070@unknown@formal@none@1@S@Scoring models process a customer’s [[credit history]], [[loan application]], customer data, etc., in order to rank-order individuals by their likelihood of making future credit payments on time.@@@@1@27@@danf@17-8-2009 10710080@unknown@formal@none@1@S@Predictive analytics are also used in [[insurance]], [[telecommunications]], [[retail]], [[travel]], [[healthcare]], [[Pharmaceutical company|pharmaceuticals]] and other fields.@@@@1@16@@danf@17-8-2009 10710090@unknown@formal@none@1@S@== Types of predictive analytics ==@@@@1@6@@danf@17-8-2009 10710100@unknown@formal@none@1@S@Generally, predictive analytics is used to mean [[predictive modeling]], scoring of predictive models, and [[forecasting]].@@@@1@15@@danf@17-8-2009 10710110@unknown@formal@none@1@S@However, people are increasingly using the term to describe related analytic disciplines, such as descriptive modeling and decision modeling or optimization.@@@@1@21@@danf@17-8-2009 10710120@unknown@formal@none@1@S@These disciplines also involve rigorous data analysis, and are widely used in business for segmentation and decision making, but have different purposes and the statistical techniques underlying them vary.@@@@1@29@@danf@17-8-2009 10710130@unknown@formal@none@1@S@===Predictive models===@@@@1@2@@danf@17-8-2009 10710140@unknown@formal@none@1@S@Predictive models analyze past performance to assess how likely a customer is to exhibit a specific behavior in the future in order to improve [[marketing effectiveness]].@@@@1@26@@danf@17-8-2009 10710150@unknown@formal@none@1@S@This category also encompasses models that seek out subtle data patterns to answer questions about customer performance, such as fraud detection models.@@@@1@22@@danf@17-8-2009 10710160@unknown@formal@none@1@S@Predictive models often perform calculations during live transactions, for example, to evaluate the risk or opportunity of a given customer or transaction, in order to guide a decision.@@@@1@28@@danf@17-8-2009 10710170@unknown@formal@none@1@S@===Descriptive models===@@@@1@2@@danf@17-8-2009 10710180@unknown@formal@none@1@S@Descriptive models “describe” relationships in data in a way that is often used to classify customers or prospects into groups.@@@@1@20@@danf@17-8-2009 10710190@unknown@formal@none@1@S@Unlike predictive models that focus on predicting a single customer behavior (such as credit risk), descriptive models identify many different relationships between customers or products.@@@@1@25@@danf@17-8-2009 10710200@unknown@formal@none@1@S@But the descriptive models do not rank-order customers by their likelihood of taking a particular action the way predictive models do.@@@@1@21@@danf@17-8-2009 10710210@unknown@formal@none@1@S@Descriptive models are often used “offline,” for example, to categorize customers by their product preferences and life stage.@@@@1@18@@danf@17-8-2009 10710220@unknown@formal@none@1@S@Descriptive modeling tools can be utilized to develop agent based models that can simulate large number of individualized agents to predict possible futures.@@@@1@23@@danf@17-8-2009 10710230@unknown@formal@none@1@S@===Decision models===@@@@1@2@@danf@17-8-2009 10710240@unknown@formal@none@1@S@Decision models describe the relationship between all the elements of a decision — the known data (including results of predictive models), the decision and the forecast results of the decision — in order to predict the results of decisions involving many variables.@@@@1@42@@danf@17-8-2009 10710250@unknown@formal@none@1@S@These models can be used in optimization, a data-driven approach to improving decision logic that involves maximizing certain outcomes while minimizing others.@@@@1@22@@danf@17-8-2009 10710260@unknown@formal@none@1@S@Decision models are generally used offline, to develop decision logic or a set of business rules that will produce the desired action for every customer or circumstance.@@@@1@27@@danf@17-8-2009 10710270@unknown@formal@none@1@S@== Predictive analytics ==@@@@1@4@@danf@17-8-2009 10710280@unknown@formal@none@1@S@===Definition===@@@@1@1@@danf@17-8-2009 10710290@unknown@formal@none@1@S@Predictive analytics is an area of statistical analysis that deals with extracting information from data and using it to predict future trends and behavior patterns.@@@@1@25@@danf@17-8-2009 10710300@unknown@formal@none@1@S@The core of predictive analytics relies on capturing relationships between explanatory variables and the predicted variables from past occurrences, and exploiting it to predict future outcomes.@@@@1@26@@danf@17-8-2009 10710310@unknown@formal@none@1@S@===Current uses===@@@@1@2@@danf@17-8-2009 10710320@unknown@formal@none@1@S@Although predictive analytics can be put to use in many applications, we outline a few examples where predictive analytics has shown positive impact in recent years.@@@@1@26@@danf@17-8-2009 10710330@unknown@formal@none@1@S@====Analytical Customer Relationship Management (CRM)====@@@@1@5@@danf@17-8-2009 10710340@unknown@formal@none@1@S@Analytical [[Customer Relationship Management]] is a frequent commercial application of Predictive Analysis.@@@@1@12@@danf@17-8-2009 10710350@unknown@formal@none@1@S@Methods of predictive analysis are applied to customer data to pursue CRM objectives.@@@@1@13@@danf@17-8-2009 10710360@unknown@formal@none@1@S@====Direct marketing====@@@@1@2@@danf@17-8-2009 10710370@unknown@formal@none@1@S@Product [[marketing]] is constantly faced with the challenge of coping with the increasing number of competing products, different consumer preferences and the variety of methods (channels) available to interact with each consumer.@@@@1@32@@danf@17-8-2009 10710380@unknown@formal@none@1@S@Efficient marketing is a process of understanding the amount of variability and tailoring the marketing strategy for greater profitability.@@@@1@19@@danf@17-8-2009 10710390@unknown@formal@none@1@S@Predictive analytics can help identify consumers with a higher likelihood of responding to a particular marketing offer.@@@@1@17@@danf@17-8-2009 10710400@unknown@formal@none@1@S@Models can be built using data from consumers’ past purchasing history and past response rates for each channel.@@@@1@18@@danf@17-8-2009 10710410@unknown@formal@none@1@S@Additional information about the consumers demographic, geographic and other characteristics can be used to make more accurate predictions.@@@@1@18@@danf@17-8-2009 10710420@unknown@formal@none@1@S@Targeting only these consumers can lead to substantial increase in response rate which can lead to a significant reduction in cost per acquisition.@@@@1@23@@danf@17-8-2009 10710430@unknown@formal@none@1@S@Apart from identifying prospects, predictive analytics can also help to identify the most effective combination of products and marketing channels that should be used to target a given consumer.@@@@1@29@@danf@17-8-2009 10710440@unknown@formal@none@1@S@====Cross-sell====@@@@1@1@@danf@17-8-2009 10710450@unknown@formal@none@1@S@Often corporate organizations collect and maintain abundant data (e.g. customer records, sale transactions) and exploiting hidden relationships in the data can provide a competitive advantage to the organization.@@@@1@28@@danf@17-8-2009 10710460@unknown@formal@none@1@S@For an organization that offers multiple products, an analysis of existing customer behavior can lead to efficient [[cross-selling|cross sell]] of products.@@@@1@21@@danf@17-8-2009 10710470@unknown@formal@none@1@S@This directly leads to higher profitability per customer and strengthening of the customer relationship.@@@@1@14@@danf@17-8-2009 10710480@unknown@formal@none@1@S@Predictive analytics can help analyze customers’ spending, usage and other behavior, and help cross-sell the right product at the right time.@@@@1@21@@danf@17-8-2009 10710490@unknown@formal@none@1@S@====Customer retention====@@@@1@2@@danf@17-8-2009 10710500@unknown@formal@none@1@S@With the amount of competing services available, businesses need to focus efforts on maintaining continuous [[consumer satisfaction]].@@@@1@17@@danf@17-8-2009 10710510@unknown@formal@none@1@S@In such a competitive scenario, [[consumer loyalty]] needs to be rewarded and [[customer attrition]] needs to be minimized.@@@@1@18@@danf@17-8-2009 10710520@unknown@formal@none@1@S@Businesses tend to respond to customer attrition on a reactive basis, acting only after the customer has initiated the process to terminate service.@@@@1@23@@danf@17-8-2009 10710530@unknown@formal@none@1@S@At this stage, the chance of changing the customer’s decision is almost impossible.@@@@1@13@@danf@17-8-2009 10710540@unknown@formal@none@1@S@Proper application of predictive analytics can lead to a more proactive retention strategy.@@@@1@13@@danf@17-8-2009 10710550@unknown@formal@none@1@S@By a frequent examination of a customer’s past service usage, service performance, spending and other behavior patterns, predictive models can determine the likelihood of a customer wanting to terminate service sometime in the near future.@@@@1@35@@danf@17-8-2009 10710560@unknown@formal@none@1@S@An intervention with lucrative offers can increase the chance of retaining the customer.@@@@1@13@@danf@17-8-2009 10710570@unknown@formal@none@1@S@Silent attrition is the behavior of a customer to slowly but steadily reduce usage and is another problem faced by many companies.@@@@1@22@@danf@17-8-2009 10710580@unknown@formal@none@1@S@Predictive analytics can also predict this behavior accurately and before it occurs, so that the company can take proper actions to increase customer activity.@@@@1@24@@danf@17-8-2009 10710590@unknown@formal@none@1@S@====Underwriting====@@@@1@1@@danf@17-8-2009 10710600@unknown@formal@none@1@S@Many businesses have to account for risk exposure due to their different services and determine the cost needed to cover the risk.@@@@1@22@@danf@17-8-2009 10710610@unknown@formal@none@1@S@For example, auto insurance providers need to accurately determine the amount of premium to charge to cover each automobile and driver.@@@@1@21@@danf@17-8-2009 10710620@unknown@formal@none@1@S@A financial company needs to assess a borrower’s potential and ability to pay before granting a loan.@@@@1@17@@danf@17-8-2009 10710630@unknown@formal@none@1@S@For a health insurance provider, predictive analytics can analyze a few years of past medical claims data, as well as lab, pharmacy and other records where available, to predict how expensive an enrollee is likely to be in the future.@@@@1@40@@danf@17-8-2009 10710640@unknown@formal@none@1@S@Predictive analytics can help [[underwriting]] of these quantities by predicting the chances of illness, [[Default (finance)|default]], [[bankruptcy]], etc.@@@@1@18@@danf@17-8-2009 10710650@unknown@formal@none@1@S@Predictive analytics can streamline the process of customer acquisition, by predicting the future risk behavior of a customer using application level data.@@@@1@22@@danf@17-8-2009 10710660@unknown@formal@none@1@S@Proper predictive analytics can lead to proper pricing decisions, which can help mitigate future risk of default.@@@@1@17@@danf@17-8-2009 10710670@unknown@formal@none@1@S@====Collection analytics====@@@@1@2@@danf@17-8-2009 10710680@unknown@formal@none@1@S@Every portfolio has a set of delinquent customers who do not make their payments on time.@@@@1@16@@danf@17-8-2009 10710690@unknown@formal@none@1@S@The financial institution has to undertake collection activities on these customers to recover the amounts due.@@@@1@16@@danf@17-8-2009 10710700@unknown@formal@none@1@S@A lot of collection resources are wasted on customers who are difficult or impossible to recover.@@@@1@16@@danf@17-8-2009 10710710@unknown@formal@none@1@S@Predictive analytics can help optimize the allocation of collection resources by identifying the most effective collection agencies, contact strategies, legal actions and other strategies to each customer, thus significantly increasing recovery at the same time reducing collection costs.@@@@1@38@@danf@17-8-2009 10710720@unknown@formal@none@1@S@====Fraud detection====@@@@1@2@@danf@17-8-2009 10710730@unknown@formal@none@1@S@Fraud is a big problem for many businesses and can be of various types.@@@@1@14@@danf@17-8-2009 10710740@unknown@formal@none@1@S@Inaccurate credit applications, fraudulent transactions, [[identity theft]]s and false insurance claims are some examples of this problem.@@@@1@17@@danf@17-8-2009 10710750@unknown@formal@none@1@S@These problems plague firms all across the spectrum and some examples of likely victims are [[Credit card fraud|credit card issuers]], insurance companies, retail merchants, manufacturers, business to business suppliers and even services providers.@@@@1@33@@danf@17-8-2009 10710760@unknown@formal@none@1@S@This is an area where a predictive model is often used to help weed out the “bads” and reduce a business's exposure to fraud.@@@@1@24@@danf@17-8-2009 10710770@unknown@formal@none@1@S@====Portfolio, product or economy level prediction====@@@@1@6@@danf@17-8-2009 10710780@unknown@formal@none@1@S@Often the focus of analysis is not the consumer but the product, portfolio, firm, industry or even the economy.@@@@1@19@@danf@17-8-2009 10710790@unknown@formal@none@1@S@For example a retailer might be interested in predicting store level demand for inventory management purposes.@@@@1@16@@danf@17-8-2009 10710800@unknown@formal@none@1@S@Or the Federal Reserve Board might be interested in predicting the unemployment rate for the next year.@@@@1@17@@danf@17-8-2009 10710810@unknown@formal@none@1@S@These type of problems can be addressed by predictive analytics using Time Series techniques (see below).@@@@1@16@@danf@17-8-2009 10710820@unknown@formal@none@1@S@Wrong Information....@@@@1@2@@danf@17-8-2009 10710830@unknown@formal@none@1@S@==Statistical techniques==@@@@1@2@@danf@17-8-2009 10710840@unknown@formal@none@1@S@The approaches and techniques used to conduct predictive analytics can broadly be grouped into regression techniques and machine learning techniques.@@@@1@20@@danf@17-8-2009 10710850@unknown@formal@none@1@S@====Regression Techniques====@@@@1@2@@danf@17-8-2009 10710860@unknown@formal@none@1@S@Regression models are the mainstay of predictive analytics.@@@@1@8@@danf@17-8-2009 10710870@unknown@formal@none@1@S@The focus lies on establishing a mathematical equation as a model to represent the interactions between the different variables in consideration.@@@@1@21@@danf@17-8-2009 10710880@unknown@formal@none@1@S@Depending on the situation, there is a wide variety of models that can be applied while performing predictive analytics.@@@@1@19@@danf@17-8-2009 10710890@unknown@formal@none@1@S@Some of them are briefly discussed below.@@@@1@7@@danf@17-8-2009 10710900@unknown@formal@none@1@S@=====Linear Regression Model=====@@@@1@3@@danf@17-8-2009 10710910@unknown@formal@none@1@S@The linear regression model analyzes the relationship between the response or dependent variable and a set of independent or predictor variables.@@@@1@21@@danf@17-8-2009 10710920@unknown@formal@none@1@S@This relationship is expressed as an equation that predicts the response variable as a linear function of the parameters.@@@@1@19@@danf@17-8-2009 10710930@unknown@formal@none@1@S@These parameters are adjusted so that a measure of fit is optimized.@@@@1@12@@danf@17-8-2009 10710940@unknown@formal@none@1@S@Much of the effort in model fitting is focused on minimizing the size of the residual, as well as ensuring that it is randomly distributed with respect to the model predictions.@@@@1@31@@danf@17-8-2009 10710950@unknown@formal@none@1@S@The goal of regression is to select the parameters of the model so as to minimize the sum of the squared residuals.@@@@1@22@@danf@17-8-2009 10710960@unknown@formal@none@1@S@This is referred to as '''[[ordinary least squares]]''' (OLS) estimation and results in best linear unbiased estimates (BLUE) of the parameters if and only if the [[Gauss–Markov theorem|Gauss-Markowitz]] assumptions are satisfied.@@@@1@31@@danf@17-8-2009 10710970@unknown@formal@none@1@S@Once the model has been estimated we would be interested to know if the predictor variables belong in the model – i.e. is the estimate of each variable’s contribution reliable?@@@@1@30@@danf@17-8-2009 10710980@unknown@formal@none@1@S@To do this we can check the statistical significance of the model’s coefficients which can be measured using the t-statistic.@@@@1@20@@danf@17-8-2009 10710990@unknown@formal@none@1@S@This amounts to testing whether the coefficient is significantly different from zero.@@@@1@12@@danf@17-8-2009 10711000@unknown@formal@none@1@S@How well the model predicts the dependent variable based on the value of the independent variables can be assessed by using the R² statistic.@@@@1@24@@danf@17-8-2009 10711010@unknown@formal@none@1@S@It measures predictive power of the model i.e. the proportion of the total variation in the dependent variable that is “explained” (accounted for) by variation in the independent variables.@@@@1@29@@danf@17-8-2009 10711020@unknown@formal@none@1@S@====Discrete choice models====@@@@1@3@@danf@17-8-2009 10711030@unknown@formal@none@1@S@Multivariate regression (above) is generally used when the response variable is continuous and has an unbounded range.@@@@1@17@@danf@17-8-2009 10711040@unknown@formal@none@1@S@Often the response variable may not be continuous but rather discrete.@@@@1@11@@danf@17-8-2009 10711050@unknown@formal@none@1@S@While mathematically it is feasible to apply multivariate regression to discrete ordered dependent variables, some of the assumptions behind the theory of multivariate linear regression no longer hold, and there are other techniques such as discrete choice models which are better suited for this type of analysis.@@@@1@47@@danf@17-8-2009 10711060@unknown@formal@none@1@S@If the dependent variable is discrete, some of those superior methods are [[logistic regression]], [[multinomial logit]] and [[probit]] models.@@@@1@19@@danf@17-8-2009 10711070@unknown@formal@none@1@S@Logistic regression and probit models are used when the dependent variable is [[binary numeral system|binary]].@@@@1@15@@danf@17-8-2009 10711080@unknown@formal@none@1@S@=====Logistic regression=====@@@@1@2@@danf@17-8-2009 10711090@unknown@formal@none@1@S@In a classification setting, assigning outcome probabilities to observations can be achieved through the use of a logistic model, which is basically a method which transforms information about the binary dependent variable into an unbounded continuous variable and estimates a regular multivariate model (See Allison’s Logistic Regression for more information on the theory of Logistic Regression).@@@@1@56@@danf@17-8-2009 10711100@unknown@formal@none@1@S@The [[Wald test|Wald]] and [[likelihood-ratio test]] are used to test the statistical significance of each coefficient b in the model (analogous to the t tests used in OLS regression; see above).@@@@1@31@@danf@17-8-2009 10711110@unknown@formal@none@1@S@A test assessing the goodness-of-fit of a classification model is the [[Hosmer and Lemeshow test]].@@@@1@15@@danf@17-8-2009 10711120@unknown@formal@none@1@S@=====Multinomial logistic regression=====@@@@1@3@@danf@17-8-2009 10711130@unknown@formal@none@1@S@An extension of the [[binary logit model]] to cases where the dependent variable has more than 2 categories is the [[multinomial logit model]].@@@@1@23@@danf@17-8-2009 10711140@unknown@formal@none@1@S@In such cases collapsing the data into two categories might not make good sense or may lead to loss in the richness of the data.@@@@1@25@@danf@17-8-2009 10711150@unknown@formal@none@1@S@The multinomial logit model is the appropriate technique in these cases, especially when the dependent variable categories are not ordered (for examples colors like red, blue, green).@@@@1@27@@danf@17-8-2009 10711160@unknown@formal@none@1@S@Some authors have extended multinomial regression to include feature selection/importance methods such as [[Random multinomial logit]].@@@@1@16@@danf@17-8-2009 10711170@unknown@formal@none@1@S@=====Probit regression=====@@@@1@2@@danf@17-8-2009 10711180@unknown@formal@none@1@S@Probit models offer an alternative to logistic regression for modeling categorical dependent variables.@@@@1@13@@danf@17-8-2009 10711190@unknown@formal@none@1@S@Even though the outcomes tend to be similar, the underlying distributions are different.@@@@1@13@@danf@17-8-2009 10711200@unknown@formal@none@1@S@Probit models are popular in social sciences like economics.@@@@1@9@@danf@17-8-2009 10711210@unknown@formal@none@1@S@A good way to understand the key difference between probit and logit models, is to assume that there is a latent variable z.@@@@1@23@@danf@17-8-2009 10711220@unknown@formal@none@1@S@We do not observe z but instead observe y which takes the value 0 or 1.@@@@1@16@@danf@17-8-2009 10711230@unknown@formal@none@1@S@In the logit model we assume that follows a logistic distribution.@@@@1@11@@danf@17-8-2009 10711240@unknown@formal@none@1@S@In the probit model we assume that follows a standard normal distribution.@@@@1@12@@danf@17-8-2009 10711250@unknown@formal@none@1@S@Note that in social sciences (example economics), probit is often used to model situations where the observed variable y is continuous but takes values between 0 and 1.@@@@1@28@@danf@17-8-2009 10711260@unknown@formal@none@1@S@=====Logit vs. Probit=====@@@@1@3@@danf@17-8-2009 10711270@unknown@formal@none@1@S@The Probit model has been around longer than the logit model.@@@@1@11@@danf@17-8-2009 10711280@unknown@formal@none@1@S@They look identical, except that the logistic distribution tends to be a little flat tailed.@@@@1@15@@danf@17-8-2009 10711290@unknown@formal@none@1@S@In fact one of the reasons the logit model was formulated was that the probit model was extremely hard to compute because it involved calculating difficult integrals.@@@@1@27@@danf@17-8-2009 10711300@unknown@formal@none@1@S@Modern computing however has made this computation fairly simple.@@@@1@9@@danf@17-8-2009 10711310@unknown@formal@none@1@S@The coefficients obtained from the logit and probit model are also fairly close.@@@@1@13@@danf@17-8-2009 10711320@unknown@formal@none@1@S@However the odds ratio makes the logit model easier to interpret.@@@@1@11@@danf@17-8-2009 10711330@unknown@formal@none@1@S@For practical purposes the only reasons for choosing the probit model over the logistic model would be:@@@@1@17@@danf@17-8-2009 10711340@unknown@formal@none@1@S@* There is a strong belief that the underlying distribution is normal@@@@1@12@@danf@17-8-2009 10711350@unknown@formal@none@1@S@* The actual event is not a binary outcome (e.g. Bankrupt/not bankrupt) but a proportion (e.g. Proportion of population at different debt levels).@@@@1@23@@danf@17-8-2009 10711360@unknown@formal@none@1@S@==== Time series models====@@@@1@4@@danf@17-8-2009 10711370@unknown@formal@none@1@S@[[Time series]] models are used for predicting or forecasting the future behavior of variables.@@@@1@14@@danf@17-8-2009 10711380@unknown@formal@none@1@S@These models account for the fact that data points taken over time may have an internal structure (such as autocorrelation, trend or seasonal variation) that should be accounted for.@@@@1@29@@danf@17-8-2009 10711390@unknown@formal@none@1@S@As a result standard regression techniques cannot be applied to time series data and methodology has been developed to decompose the trend, seasonal and cyclical component of the series.@@@@1@29@@danf@17-8-2009 10711400@unknown@formal@none@1@S@Modeling the dynamic path of a variable can improve forecasts since the predictable component of the series can be projected into the future.@@@@1@23@@danf@17-8-2009 10711410@unknown@formal@none@1@S@Time series models estimate difference equations containing stochastic components.@@@@1@9@@danf@17-8-2009 10711420@unknown@formal@none@1@S@Two commonly used forms of these models are [[autoregressive model]]s (AR) and [[Moving average (technical analysis)|moving average]] (MA) models.@@@@1@19@@danf@17-8-2009 10711430@unknown@formal@none@1@S@The [[Box-Jenkins]] methodology (1976) developed by George Box and G.M. Jenkins combines the AR and MA models to produce the [[Autoregressive moving average model|ARMA]] (autoregressive moving average) model which is the cornerstone of stationary time series analysis.@@@@1@37@@danf@17-8-2009 10711440@unknown@formal@none@1@S@ARIMA (autoregressive integrated moving average models) on the other hand are used to describe non-stationary time series.@@@@1@17@@danf@17-8-2009 10711450@unknown@formal@none@1@S@Box and Jenkins suggest differencing a non stationary time series to obtain a stationary series to which an ARMA model can be applied.@@@@1@23@@danf@17-8-2009 10711460@unknown@formal@none@1@S@Non stationary time series have a pronounced trend and do not have a constant long-run mean or variance.@@@@1@18@@danf@17-8-2009 10711470@unknown@formal@none@1@S@Box and Jenkins proposed a three stage methodology which includes: model identification, estimation and validation.@@@@1@15@@danf@17-8-2009 10711480@unknown@formal@none@1@S@The identification stage involves identifying if the series is stationary or not and the presence of seasonality by examining plots of the series, autocorrelation and partial autocorrelation functions.@@@@1@28@@danf@17-8-2009 10711490@unknown@formal@none@1@S@In the estimation stage, models are estimated using non-linear time series or maximum likelihood estimation procedures.@@@@1@16@@danf@17-8-2009 10711500@unknown@formal@none@1@S@Finally the validation stage involves diagnostic checking such as plotting the residuals to detect outliers and evidence of model fit.@@@@1@20@@danf@17-8-2009 10711510@unknown@formal@none@1@S@In recent years time series models have become more sophisticated and attempt to model conditional heteroskedasticity with models such as ARCH ([[autoregressive conditional heteroskedasticity]]) and GARCH (generalized autoregressive conditional heteroskedasticity) models frequently used for financial time series.@@@@1@37@@danf@17-8-2009 10711520@unknown@formal@none@1@S@In addition time series models are also used to understand inter-relationships among economic variables represented by systems of equations using VAR (vector autoregression) and structural VAR models.@@@@1@27@@danf@17-8-2009 10711530@unknown@formal@none@1@S@==== Survival or duration analysis====@@@@1@5@@danf@17-8-2009 10711540@unknown@formal@none@1@S@[[Survival analysis]] is another name for time to event analysis.@@@@1@10@@danf@17-8-2009 10711550@unknown@formal@none@1@S@These techniques were primarily developed in the medical and biological sciences, but they are also widely used in the social sciences like economics, as well as in engineering (reliability and failure time analysis).@@@@1@33@@danf@17-8-2009 10711560@unknown@formal@none@1@S@Censoring and non-normality which are characteristic of survival data generate difficulty when trying to analyze the data using conventional statistical models such as multiple linear regression.@@@@1@26@@danf@17-8-2009 10711570@unknown@formal@none@1@S@The Normal distribution, being a symmetric distribution, takes positive as well as negative values, but duration by its very nature cannot be negative and therefore normality cannot be assumed when dealing with duration/survival data.@@@@1@34@@danf@17-8-2009 10711580@unknown@formal@none@1@S@Hence the normality assumption of regression models is violated.@@@@1@9@@danf@17-8-2009 10711590@unknown@formal@none@1@S@A censored observation is defined as an observation with incomplete information.@@@@1@11@@danf@17-8-2009 10711600@unknown@formal@none@1@S@Censoring introduces distortions into traditional statistical methods and is essentially a defect of the sample data.@@@@1@16@@danf@17-8-2009 10711610@unknown@formal@none@1@S@The assumption is that if the data were not censored it would be representative of the population of interest.@@@@1@19@@danf@17-8-2009 10711620@unknown@formal@none@1@S@In survival analysis, censored observations arise whenever the dependent variable of interest represents the time to a terminal event, and the duration of the study is limited in time.@@@@1@29@@danf@17-8-2009 10711630@unknown@formal@none@1@S@An important concept in survival analysis is the hazard rate.@@@@1@10@@danf@17-8-2009 10711640@unknown@formal@none@1@S@The hazard rate is defined as the probability that the event will occur at time t conditional on surviving until time t.@@@@1@22@@danf@17-8-2009 10711650@unknown@formal@none@1@S@Another concept related to the hazard rate is the survival function which can be defined as the probability of surviving to time t.@@@@1@23@@danf@17-8-2009 10711660@unknown@formal@none@1@S@Most models try to model the hazard rate by choosing the underlying distribution depending on the shape of the hazard function.@@@@1@21@@danf@17-8-2009 10711670@unknown@formal@none@1@S@A distribution whose hazard function slopes upward is said to have positive duration dependence, a decreasing hazard shows negative duration dependence whereas constant hazard is a process with no memory usually characterized by the exponential distribution.@@@@1@36@@danf@17-8-2009 10711680@unknown@formal@none@1@S@Some of the distributional choices in survival models are: F, gamma, Weibull, log normal, inverse normal, exponential etc.@@@@1@18@@danf@17-8-2009 10711690@unknown@formal@none@1@S@All these distributions are for a non-negative random variable.@@@@1@9@@danf@17-8-2009 10711700@unknown@formal@none@1@S@Duration models can be parametric, non-parametric or semi-parametric.@@@@1@8@@danf@17-8-2009 10711710@unknown@formal@none@1@S@Some of the models commonly used are Kaplan-Meier, Cox proportional hazard model (non parametric).@@@@1@14@@danf@17-8-2009 10711720@unknown@formal@none@1@S@==== Classification and regression trees====@@@@1@5@@danf@17-8-2009 10711730@unknown@formal@none@1@S@Classification and regression trees (CART) is a [[non-parametric statistics|non-parametric]] technique that produces either classification or regression trees, depending on whether the dependent variable is categorical or numeric, respectively.@@@@1@28@@danf@17-8-2009 10711740@unknown@formal@none@1@S@Trees are formed by a collection of rules based on values of certain variables in the modeling data set@@@@1@19@@danf@17-8-2009 10711750@unknown@formal@none@1@S@* Rules are selected based on how well splits based on variables’ values can differentiate observations based on the dependent variable@@@@1@21@@danf@17-8-2009 10711760@unknown@formal@none@1@S@* Once a rule is selected and splits a node into two, the same logic is applied to each “child” node (i.e. it is a recursive procedure)@@@@1@27@@danf@17-8-2009 10711770@unknown@formal@none@1@S@* Splitting stops when CART detects no further gain can be made, or some pre-set stopping rules are met@@@@1@19@@danf@17-8-2009 10711780@unknown@formal@none@1@S@Each branch of the tree ends in a terminal node@@@@1@10@@danf@17-8-2009 10711790@unknown@formal@none@1@S@* Each observation falls into one and exactly one terminal node@@@@1@11@@danf@17-8-2009 10711800@unknown@formal@none@1@S@* Each terminal node is uniquely defined by a set of rules@@@@1@12@@danf@17-8-2009 10711810@unknown@formal@none@1@S@A very popular method for predictive analytics is Leo Breiman's [[Random forests]] or derived versions of this technique like [[Random multinomial logit]].@@@@1@22@@danf@17-8-2009 10711820@unknown@formal@none@1@S@==== Multivariate adaptive regression splines====@@@@1@5@@danf@17-8-2009 10711830@unknown@formal@none@1@S@[[Multivariate adaptive regression splines]] (MARS) is a [[Non-parametric statistics|non-parametric]] technique that builds flexible models by fitting [[piecewise linear regression]]s.@@@@1@19@@danf@17-8-2009 10711840@unknown@formal@none@1@S@An important concept associated with regression splines is that of a knot.@@@@1@12@@danf@17-8-2009 10711850@unknown@formal@none@1@S@Knot is where one local regression model gives way to another and thus is the point of intersection between two splines.@@@@1@21@@danf@17-8-2009 10711860@unknown@formal@none@1@S@In multivariate and adaptive regression splines, [[basis function]]s are the tool used for generalizing the search for knots.@@@@1@18@@danf@17-8-2009 10711870@unknown@formal@none@1@S@Basis functions are a set of functions used to represent the information contained in one or more variables.@@@@1@18@@danf@17-8-2009 10711880@unknown@formal@none@1@S@Multivariate and Adaptive Regression Splines model almost always creates the basis functions in pairs.@@@@1@14@@danf@17-8-2009 10711890@unknown@formal@none@1@S@Multivariate and adaptive regression spline approach deliberately overfits the model and then prunes to get to the optimal model.@@@@1@19@@danf@17-8-2009 10711900@unknown@formal@none@1@S@The algorithm is computationally very intensive and in practice we are required to specify an upper limit on the number of basis functions.@@@@1@23@@danf@17-8-2009 10711910@unknown@formal@none@1@S@=== Machine learning techniques===@@@@1@4@@danf@17-8-2009 10711920@unknown@formal@none@1@S@[[Machine learning]], a branch of artificial intelligence, was originally employed to develop techniques to enable computers to learn.@@@@1@18@@danf@17-8-2009 10711930@unknown@formal@none@1@S@Today, since it includes a number of advanced statistical methods for regression and classification, it finds application in a wide variety of fields including [[medical diagnostics]], [[credit card fraud detection]], [[Face recognition|face]] and [[speech recognition]] and analysis of the [[stock market]].@@@@1@41@@danf@17-8-2009 10711940@unknown@formal@none@1@S@In certain applications it is sufficient to directly predict the dependent variable without focusing on the underlying relationships between variables.@@@@1@20@@danf@17-8-2009 10711950@unknown@formal@none@1@S@In other cases, the underlying relationships can be very complex and the mathematical form of the dependencies unknown.@@@@1@18@@danf@17-8-2009 10711960@unknown@formal@none@1@S@For such cases, machine learning techniques emulate [[human cognition]] and learn from training examples to predict future events.@@@@1@18@@danf@17-8-2009 10711970@unknown@formal@none@1@S@A brief discussion of some of these methods used commonly for predictive analytics is provided below.@@@@1@16@@danf@17-8-2009 10711980@unknown@formal@none@1@S@A detailed study of machine learning can be found in Mitchell (1997).@@@@1@12@@danf@17-8-2009 10711990@unknown@formal@none@1@S@==== Neural networks====@@@@1@3@@danf@17-8-2009 10712000@unknown@formal@none@1@S@[[Neural networks]] are [[Nonlinearity|nonlinear]] sophisticated modeling techniques that are able to [[Model (abstract)|model]] complex functions.@@@@1@15@@danf@17-8-2009 10712010@unknown@formal@none@1@S@They can be applied to problems of [[Time series|prediction]], [[Statistical classification|classification]] or [[Control theory|control]] in a wide spectrum of fields such as [[finance]], [[cognitive psychology]]/[[cognitive neuroscience|neuroscience]], [[medicine]], [[engineering]], and [[physics]].@@@@1@30@@danf@17-8-2009 10712020@unknown@formal@none@1@S@Neural networks are used when the exact nature of the relationship between inputs and output is not known.@@@@1@18@@danf@17-8-2009 10712030@unknown@formal@none@1@S@A key feature of neural networks is that they learn the relationship between inputs and output through training.@@@@1@18@@danf@17-8-2009 10712040@unknown@formal@none@1@S@There are two types of training in neural networks used by different networks, [[Supervised learning|supervised]] and [[Unsupervised learning|unsupervised]] training, with supervised being the most common one.@@@@1@26@@danf@17-8-2009 10712050@unknown@formal@none@1@S@Some examples of neural network training techniques are [[backpropagation]], quick propagation, [[Conjugate gradient method|conjugate gradient descent]], [[Radial basis function|projection operator]], Delta-Bar-Delta etc.@@@@1@22@@danf@17-8-2009 10712060@unknown@formal@none@1@S@Theses are applied to network architectures such as multilayer [[perceptron]]s, [[Self-organizing map|Kohonen network]]s, [[Hopfield network]]s, etc.@@@@1@16@@danf@17-8-2009 10712070@unknown@formal@none@1@S@====Radial basis functions====@@@@1@3@@danf@17-8-2009 10712080@unknown@formal@none@1@S@A [[radial basis function]] (RBF) is a function which has built into it a distance criterion with respect to a center.@@@@1@21@@danf@17-8-2009 10712090@unknown@formal@none@1@S@Such functions can be used very efficiently for interpolation and for smoothing of data.@@@@1@14@@danf@17-8-2009 10712100@unknown@formal@none@1@S@Radial basis functions have been applied in the area of [[neural network]]s where they are used as a replacement for the sigmoidal transfer function.@@@@1@24@@danf@17-8-2009 10712110@unknown@formal@none@1@S@Such networks have 3 layers, the input layer, the hidden layer with the RBF non-linearity and a linear output layer.@@@@1@20@@danf@17-8-2009 10712120@unknown@formal@none@1@S@The most popular choice for the non-linearity is the Gaussian.@@@@1@10@@danf@17-8-2009 10712130@unknown@formal@none@1@S@RBF networks have the advantage of not being locked into local minima as do the [[feed-forward]] networks such as the multilayer perceptron.@@@@1@22@@danf@17-8-2009 10712140@unknown@formal@none@1@S@==== Support vector machines====@@@@1@4@@danf@17-8-2009 10712150@unknown@formal@none@1@S@[[Support Vector Machine]]s (SVM) are used to detect and exploit complex patterns in data by clustering, classifying and ranking the data.@@@@1@21@@danf@17-8-2009 10712160@unknown@formal@none@1@S@They are learning machines that are used to perform binary classifications and regression estimations.@@@@1@14@@danf@17-8-2009 10712170@unknown@formal@none@1@S@They commonly use kernel based methods to apply linear classification techniques to non-linear classification problems.@@@@1@15@@danf@17-8-2009 10712180@unknown@formal@none@1@S@There are a number of types of SVM such as linear, polynomial, sigmoid etc.@@@@1@14@@danf@17-8-2009 10712190@unknown@formal@none@1@S@==== Naïve Bayes====@@@@1@3@@danf@17-8-2009 10712200@unknown@formal@none@1@S@[[Naive Bayes classifier|Naïve Bayes]] based on Bayes conditional probability rule is used for performing classification tasks.@@@@1@16@@danf@17-8-2009 10712210@unknown@formal@none@1@S@Naïve Bayes assumes the predictors are statistically independent which makes it an effective classification tool that is easy to interpret.@@@@1@20@@danf@17-8-2009 10712220@unknown@formal@none@1@S@It is best employed when faced with the problem of ‘curse of dimensionality’ i.e. when the number of predictors is very high.@@@@1@22@@danf@17-8-2009 10712230@unknown@formal@none@1@S@==== k-nearest neighbours====@@@@1@3@@danf@17-8-2009 10712240@unknown@formal@none@1@S@The [[K-nearest neighbor algorithm|nearest neighbour algorithm]] (KNN) belongs to the class of pattern recognition statistical methods.@@@@1@16@@danf@17-8-2009 10712250@unknown@formal@none@1@S@The method does not impose a priori any assumptions about the distribution from which the modeling sample is drawn.@@@@1@19@@danf@17-8-2009 10712260@unknown@formal@none@1@S@It involves a training set with both positive and negative values.@@@@1@11@@danf@17-8-2009 10712270@unknown@formal@none@1@S@A new sample is classified by calculating the distance to the nearest neighbouring training case.@@@@1@15@@danf@17-8-2009 10712280@unknown@formal@none@1@S@The sign of that point will determine the classification of the sample.@@@@1@12@@danf@17-8-2009 10712290@unknown@formal@none@1@S@In the k-nearest neighbour classifier, the k nearest points are considered and the sign of the majority is used to classify the sample.@@@@1@23@@danf@17-8-2009 10712300@unknown@formal@none@1@S@The performance of the kNN algorithm is influenced by three main factors: (1) the distance measure used to locate the nearest neighbours; (2) the decision rule used to derive a classification from the k-nearest neighbours; and (3) the number of neighbours used to classify the new sample.@@@@1@47@@danf@17-8-2009 10712310@unknown@formal@none@1@S@It can be proved that, unlike other methods, this method is universally asymptotically convergent, i.e.: as the size of the training set increases, if the observations are iid, regardless of the distribution from which the sample is drawn, the predicted class will converge to the class assignment that minimizes misclassification error.@@@@1@51@@danf@17-8-2009 10712320@unknown@formal@none@1@S@See Devroy et alt.@@@@1@4@@danf@17-8-2009 10712330@unknown@formal@none@1@S@==Popular tools==@@@@1@2@@danf@17-8-2009 10712340@unknown@formal@none@1@S@There are numerous tools available in the marketplace which help with the execution of predictive analytics.@@@@1@16@@danf@17-8-2009 10712350@unknown@formal@none@1@S@These range from those which need very little user sophistication to those that are designed for the expert practitioner.@@@@1@19@@danf@17-8-2009 10712360@unknown@formal@none@1@S@The difference between these tools is often in the level of customization and heavy data lifting allowed.@@@@1@17@@danf@17-8-2009 10712370@unknown@formal@none@1@S@For traditional statistical modeling some of the popular tools are [[DAP (software)|DAP]]/[[SAS Institute|SAS]], S-Plus, [[PSPP]]/[[SPSS]] and Stata.@@@@1@17@@danf@17-8-2009 10712380@unknown@formal@none@1@S@For machine learning/data mining type of applications, KnowledgeSEEKER, KnowledgeSTUDIO, Enterprise Miner, GeneXproTools, [[Viscovery]], Clementine, [[KXEN Inc.|KXEN Analytic Framework]], [[InforSense]] and Excel Miner are some of the popularly used options.@@@@1@29@@danf@17-8-2009 10712390@unknown@formal@none@1@S@Classification Tree analysis can be performed using CART software.@@@@1@9@@danf@17-8-2009 10712400@unknown@formal@none@1@S@SOMine is a predictive analytics tool based on [[self-organizing map]]s (SOMs) available from [[Viscovery Software]].@@@@1@15@@danf@17-8-2009 10712410@unknown@formal@none@1@S@[[R (programming_language)|R]] is a very powerful tool that can be used to perform almost any kind of statistical analysis, and is freely downloadable.@@@@1@23@@danf@17-8-2009 10712420@unknown@formal@none@1@S@[[WEKA]] is a freely available [[open source|open-source]] collection of [[machine learning]] methods for pattern classification, regression, clustering, and some types of meta-learning, which can be used for predictive analytics.@@@@1@29@@danf@17-8-2009 10712430@unknown@formal@none@1@S@[[RapidMiner]] is another freely available integrated [[open source|open-source]] software environment for predictive analytics, [[data mining]], and [[machine learning]] fully integrating WEKA and providing an even larger number of methods for predictive analytics.@@@@1@32@@danf@17-8-2009 10712440@unknown@formal@none@1@S@Recently, in an attempt to provide a standard language for expressing predictive models, the [[Predictive Model Markup Language]] (PMML) has been proposed.@@@@1@22@@danf@17-8-2009 10712450@unknown@formal@none@1@S@Such an XML-based language provides a way for the different tools to define predictive models and to share these between PMML compliant applications.@@@@1@23@@danf@17-8-2009 10712460@unknown@formal@none@1@S@Several tools already produce or consume PMML documents, these include [[ADAPA]], [[IBM DB2]] Warehouse, CART, SAS Enterprise Miner, and [[SPSS]].@@@@1@20@@danf@17-8-2009 10712470@unknown@formal@none@1@S@Predictive analytics has also found its way into the IT lexicon, most notably in the area of IT Automation.@@@@1@19@@danf@17-8-2009 10712480@unknown@formal@none@1@S@Vendors such as [[Stratavia]] and their [[Data Palette]] product offer predictive analytics as part of their automation platform, predicting how resources will behave in the future and automate the environment accordingly.@@@@1@31@@danf@17-8-2009 10712490@unknown@formal@none@1@S@The widespread use of predictive analytics in industry has led to the proliferation of numerous productized solutions firms.@@@@1@18@@danf@17-8-2009 10712500@unknown@formal@none@1@S@Some of them are highly specialized (focusing, for example, on fraud detection, automatic saleslead generation or response modeling) in a specific domain ([[Fair Isaac]] for credit card scores) or industry verticals (MarketRx in Pharmaceutical).@@@@1@34@@danf@17-8-2009 10712510@unknown@formal@none@1@S@Others provide predictive analytics services in support of a wide range of business problems across industry verticals ([[Fifth C]]).@@@@1@19@@danf@17-8-2009 10712520@unknown@formal@none@1@S@Predictive Analytics competitions are also fairly common and often pit academics and Industry practitioners (see for example, KDD CUP).@@@@1@19@@danf@17-8-2009 10712530@unknown@formal@none@1@S@==Conclusion==@@@@1@1@@danf@17-8-2009 10712540@unknown@formal@none@1@S@Predictive analytics adds great value to a businesses decision making capabilities by allowing it to formulate smart policies on the basis of predictions of future outcomes.@@@@1@26@@danf@17-8-2009 10712550@unknown@formal@none@1@S@A broad range of tools and techniques are available for this type of analysis and their selection is determined by the analytical maturity of the firm as well as the specific requirements of the problem being solved.@@@@1@37@@danf@17-8-2009 10712560@unknown@formal@none@1@S@==Education==@@@@1@1@@danf@17-8-2009 10712570@unknown@formal@none@1@S@Predictive analytics is taught at the following institutions:@@@@1@8@@danf@17-8-2009 10712580@unknown@formal@none@1@S@* Ghent University, Belgium: [http://www.mma.UGent.be Master of Marketing Analysis], an 8-month advanced master degree taught in English with strong emphasis on applications of predictive analytics in Analytical CRM.@@@@1@28@@danf@17-8-2009 10720010@unknown@formal@none@1@S@
RapidMiner
@@@@1@1@@danf@17-8-2009 10720020@unknown@formal@none@1@S@'''RapidMiner''' (formerly YALE (Yet Another Learning Environment)) is an environment for [[machine learning]] and [[data mining]] experiments.@@@@1@17@@danf@17-8-2009 10720030@unknown@formal@none@1@S@It allows experiments to be made up of a large number of arbitrarily nestable operators, described in [[XML]] files which can easily be created with RapidMiner's [[graphical user interface]].@@@@1@29@@danf@17-8-2009 10720040@unknown@formal@none@1@S@Applications of RapidMiner cover both research and real-world data mining tasks.@@@@1@11@@danf@17-8-2009 10720050@unknown@formal@none@1@S@The initial version has been developed by the Artificial Intelligence Unit of [[Dortmund University of Technology|University of Dortmund]] since [[2001]].@@@@1@20@@danf@17-8-2009 10720060@unknown@formal@none@1@S@It is distributed under a [[GNU]] license, and has been hosted by [[SourceForge]] since [[2004]].@@@@1@15@@danf@17-8-2009 10720070@unknown@formal@none@1@S@RapidMiner provides more than 400 operators for all main machine learning procedures, including input and output, and data preprocessing and visualization.@@@@1@21@@danf@17-8-2009 10720080@unknown@formal@none@1@S@It is written in the [[Java (programming language)|Java programming language]] and therefore can work on all popular operating systems.@@@@1@19@@danf@17-8-2009 10720090@unknown@formal@none@1@S@It also integrates all learning schemes and attribute evaluators of the [[Weka (machine learning)|Weka]] learning environment.@@@@1@16@@danf@17-8-2009 10720100@unknown@formal@none@1@S@== Properties ==@@@@1@3@@danf@17-8-2009 10720110@unknown@formal@none@1@S@Some properties of RapidMiner are:@@@@1@5@@danf@17-8-2009 10720120@unknown@formal@none@1@S@* written in Java@@@@1@4@@danf@17-8-2009 10720130@unknown@formal@none@1@S@* [[knowledge discovery]] processes are modeled as operator trees@@@@1@9@@danf@17-8-2009 10720140@unknown@formal@none@1@S@* internal XML representation ensures standardized interchange format of data mining experiments@@@@1@12@@danf@17-8-2009 10720150@unknown@formal@none@1@S@* scripting language allows for automatic large-scale experiments@@@@1@8@@danf@17-8-2009 10720160@unknown@formal@none@1@S@* multi-layered data view concept ensures efficient and transparent data handling@@@@1@11@@danf@17-8-2009 10720170@unknown@formal@none@1@S@* [[graphical user interface]], [[command line]] mode ([[Batch file|batch mode]]), and [[Java API]] for using RapidMiner from your own programs@@@@1@20@@danf@17-8-2009 10720180@unknown@formal@none@1@S@* [[plugin]] and [[Extension (computing)|extension]] mechanisms, several plugins already exist@@@@1@10@@danf@17-8-2009 10720190@unknown@formal@none@1@S@* [[plotting]] facility offering a large set of high-dimensional visualization schemes for data and models@@@@1@15@@danf@17-8-2009 10720200@unknown@formal@none@1@S@* applications include [[text mining]], multimedia mining, feature engineering, data stream mining and tracking drifting concepts, development of ensemble methods, and distributed data mining.@@@@1@24@@danf@17-8-2009 10730010@unknown@formal@none@1@S@
Russian language
@@@@1@2@@danf@17-8-2009 10730020@unknown@formal@none@1@S@'''Russian''' ([[:Media:Ru-russkiy jizyk.ogg|]] ([[Wikipedia:Media help|help]]•[[:Image:Ru-russkiy jizyk.ogg|info]]), [[Romanization of Russian|transliteration]]: , {{IPA-ru|ˈruskʲɪj jɪˈzɨk}}) is the most geographically widespread language of [[Eurasia]], the most widely spoken of the [[Slavic languages]], and the largest [[native language]] in [[Europe]].@@@@1@38@@danf@17-8-2009 10730030@unknown@formal@none@1@S@Russian belongs to the family of [[Indo-European languages]] and is one of three (or, according to some authorities , four) living members of the [[East Slavic languages]], the others being [[Belarusian language|Belarusian]] and [[Ukrainian language|Ukrainian]] (and possibly [[Rusyn language|Rusyn]], often considered a dialect of Ukrainian).@@@@1@45@@danf@17-8-2009 10730040@unknown@formal@none@1@S@It is also spoken by the countries of the [[Russophone]].@@@@1@10@@danf@17-8-2009 10730050@unknown@formal@none@1@S@Written examples of Old East Slavonic are attested from the 10th century onwards.@@@@1@13@@danf@17-8-2009 10730060@unknown@formal@none@1@S@Today Russian is widely used outside [[Russia]].@@@@1@7@@danf@17-8-2009 10730070@unknown@formal@none@1@S@It is applied as a means of coding and storage of universal knowledge — 60–70% of all world information is published in English and Russian languages.@@@@1@26@@danf@17-8-2009 10730080@unknown@formal@none@1@S@Over a quarter of the world's scientific literature is published in Russian.@@@@1@12@@danf@17-8-2009 10730090@unknown@formal@none@1@S@Russian is also a necessary accessory of world communications systems (broadcasts, air- and space communication, etc).@@@@1@16@@danf@17-8-2009 10730100@unknown@formal@none@1@S@Due to the status of the [[Soviet Union]] as a [[superpower]], Russian had great political importance in the 20th century.@@@@1@20@@danf@17-8-2009 10730110@unknown@formal@none@1@S@Hence, the language is one of the [[United Nations#Languages|official languages]] of the [[United Nations]].@@@@1@14@@danf@17-8-2009 10730120@unknown@formal@none@1@S@Russian distinguishes between [[consonant]] [[phoneme]]s with [[palatalization|palatal]] [[secondary articulation]] and those without, the so-called ''soft'' and ''hard'' sounds.@@@@1@18@@danf@17-8-2009 10730130@unknown@formal@none@1@S@This distinction is found between pairs of almost all consonants and is one of the most distinguishing features of the language.@@@@1@21@@danf@17-8-2009 10730140@unknown@formal@none@1@S@Another important aspect is the [[vowel reduction|reduction]] of [[stress (linguistics)|unstressed]] [[vowel]]s, which is somewhat similar to [[Unstressed and reduced vowels in English|that of English]].@@@@1@24@@danf@17-8-2009 10730150@unknown@formal@none@1@S@Stress, which is unpredictable, is not normally indicated orthographically.@@@@1@9@@danf@17-8-2009 10730160@unknown@formal@none@1@S@According to the Institute of Russian Language of the Russian Academy of Sciences, an optional [[acute accent]] () may, and sometimes should, be used to mark stress.@@@@1@27@@danf@17-8-2009 10730170@unknown@formal@none@1@S@For example, it is used to distinguish between otherwise identical words, especially when context doesn't make it obvious: ''замо́к/за́мок'' (lock/castle), ''сто́ящий/стоя́щий'' (worthwhile/standing), ''чудно́/чу́дно'' (this is odd/this is marvellous), ''молоде́ц/мо́лодец'' (attaboy/fine young man), ''узна́ю/узнаю́'' (I shall learn it/I am learning it), ''отреза́ть/отре́зать'' (infinitive for "cut"/perfective for "cut"); to indicate the proper pronouncation of uncommon words, especially personal and family names (''афе́ра, гу́ру, Гарси́а, Оле́ша, Фе́рми''), and to express the stressed word in the sentence (''Ты́ съел печенье?/Ты съе́л печенье?/Ты съел пече́нье?'' - Was it you who eat the cookie?/Did you eat the cookie?/Was the cookie your meal?).@@@@1@96@@danf@17-8-2009 10730180@unknown@formal@none@1@S@Acute accents are mandatory in lexical dictionaries and books intended to be used either by children or foreign readers.@@@@1@19@@danf@17-8-2009 10730190@unknown@formal@none@1@S@==Classification==@@@@1@1@@danf@17-8-2009 10730200@unknown@formal@none@1@S@Russian is a [[Slavic languages|Slavic language]] in the [[Indo-European Languages|Indo-European family]].@@@@1@11@@danf@17-8-2009 10730210@unknown@formal@none@1@S@From the point of view of the [[spoken language]], its closest relatives are [[Ukrainian language|Ukrainian]] and [[Belarusian language|Belarusian]], the other two national languages in the [[East Slavic languages|East Slavic]] group.@@@@1@30@@danf@17-8-2009 10730220@unknown@formal@none@1@S@In many places in eastern [[Ukraine]] and [[Belarus]], these languages are spoken interchangeably, and in certain areas traditional bilingualism resulted in language mixture, e.g. [[Surzhyk]] in eastern Ukraine and [[Trasianka]] in Belarus.@@@@1@32@@danf@17-8-2009 10730240@unknown@formal@none@1@S@An East Slavic [[Old Novgorod dialect]], although vanished during the fifteenth or sixteenth century, is sometimes considered to have played a significant role in formation of the modern Russian language.@@@@1@30@@danf@17-8-2009 10730250@unknown@formal@none@1@S@The vocabulary (mainly abstract and literary words), principles of word formation, and, to some extent, inflections and literary style of Russian have been also influenced by [[Church Slavonic language|Church Slavonic]], a developed and partly adopted form of the [[South Slavic languages|South Slavic]] [[Old Church Slavonic]] language used by the [[Russian Orthodox Church]].@@@@1@52@@danf@17-8-2009 10730260@unknown@formal@none@1@S@However, the East Slavic forms have tended to be used exclusively in the various dialects that are experiencing a rapid decline.@@@@1@21@@danf@17-8-2009 10730270@unknown@formal@none@1@S@In some cases, both the [[East Slavic languages|East Slavic]] and the [[Church Slavonic]] forms are in use, with slightly different meanings.@@@@1@21@@danf@17-8-2009 10730280@unknown@formal@none@1@S@''For details, see [[Russian phonology]] and [[History of the Russian language]].''@@@@1@11@@danf@17-8-2009 10730290@unknown@formal@none@1@S@Russian phonology and syntax (especially in northern dialects) have also been influenced to some extent by the numerous Finnic languages of the [[Finno-Ugric languages|Finno-Ugric subfamily]]: [[Merya language|Merya]], [[Moksha language|Moksha]], [[Muromian language|Muromian]], the language of the [[Meshchera]], [[Veps language|Veps]], et cetera.@@@@1@40@@danf@17-8-2009 10730300@unknown@formal@none@1@S@These languages, some of them now extinct, used to be spoken in the center and in the north of what is now the European part of Russia.@@@@1@27@@danf@17-8-2009 10730310@unknown@formal@none@1@S@They came in contact with Eastern Slavic as far back as the early Middle Ages and eventually served as substratum for the modern Russian language.@@@@1@25@@danf@17-8-2009 10730320@unknown@formal@none@1@S@The Russian dialects spoken north, north-east and north-west of [[Moscow]] have a considerable number of words of Finno-Ugric origin.@@@@1@19@@danf@17-8-2009 10730330@unknown@formal@none@1@S@Over the course of centuries, the vocabulary and literary style of Russian have also been influenced by Turkic/Caucasian/Central Asian languages, as well as Western/Central European languages such as [[Polish language|Polish]], [[Latin]], [[Dutch language|Dutch]], [[German language|German]], [[French language|French]], and [[English language|English]].@@@@1@40@@danf@17-8-2009 10730340@unknown@formal@none@1@S@According to the [[Defense Language Institute]] in [[Monterey, California]], Russian is classified as a level III language in terms of learning difficulty for native English speakers, requiring approximately 780 hours of immersion instruction to achieve intermediate fluency.@@@@1@37@@danf@17-8-2009 10730350@unknown@formal@none@1@S@It is also regarded by the [[United States Intelligence Community]] as a "hard target" language, due to both its difficulty to master for English speakers as well as due to its critical role in American world policy.@@@@1@37@@danf@17-8-2009 10730360@unknown@formal@none@1@S@==Geographic distribution==@@@@1@2@@danf@17-8-2009 10730370@unknown@formal@none@1@S@Russian is primarily spoken in [[Russia]] and, to a lesser extent, the other countries that were once constituent republics of the [[Soviet Union|USSR]].@@@@1@23@@danf@17-8-2009 10730380@unknown@formal@none@1@S@Until [[1917]], it was the sole official language of the [[Russian Empire]].@@@@1@12@@danf@17-8-2009 10730390@unknown@formal@none@1@S@During the Soviet period, the policy toward the languages of the various other ethnic groups fluctuated in practice.@@@@1@18@@danf@17-8-2009 10730400@unknown@formal@none@1@S@Though each of the constituent republics had its own official language, the unifying role and superior status was reserved for Russian.@@@@1@21@@danf@17-8-2009 10730410@unknown@formal@none@1@S@Following the break-up of [[1991]], several of the newly independent states have encouraged their native languages, which has partly reversed the privileged status of Russian, though its role as the language of post-Soviet national intercourse throughout the region has continued.@@@@1@40@@danf@17-8-2009 10730420@unknown@formal@none@1@S@In [[Latvia]], notably, its official recognition and legality in the classroom have been a topic of considerable debate in a country where more than one-third of the population is Russian-speaking, consisting mostly of post-[[World War II]] immigrants from Russia and other parts of the former [[USSR]] (Belarus, Ukraine).@@@@1@48@@danf@17-8-2009 10730430@unknown@formal@none@1@S@Similarly, in [[Estonia]], the Soviet-era immigrants and their Russian-speaking descendants constitute 25,6% of the country's current population and 58,6% of the native Estonian population is also able to speak Russian.@@@@1@30@@danf@17-8-2009 10730440@unknown@formal@none@1@S@In all, 67,8% of Estonia's population can speak Russian.@@@@1@9@@danf@17-8-2009 10730450@unknown@formal@none@1@S@In [[Kazakhstan]] and [[Kyrgyzstan]], Russian remains a co-official language with [[Kazakh language|Kazakh]] and [[Kyrgyz language|Kyrgyz]] respectively.@@@@1@16@@danf@17-8-2009 10730460@unknown@formal@none@1@S@Large Russian-speaking communities still exist in northern Kazakhstan, and ethnic Russians comprise 25.6 % of Kazakhstan's population.@@@@1@17@@danf@17-8-2009 10730470@unknown@formal@none@1@S@A much smaller Russian-speaking minority in [[Lithuania]] has represented less than 1/10 of the country's overall population.@@@@1@17@@danf@17-8-2009 10730480@unknown@formal@none@1@S@Nevertheless more than half of the population of the [[Baltic states]] are able to hold a conversation in Russian and almost all have at least some familiarity with the most basic spoken and written phrases.@@@@1@35@@danf@17-8-2009 10730490@unknown@formal@none@1@S@The Russian control of [[Finland]] in 1809–1918, however, has left few Russian speakers in Finland.@@@@1@15@@danf@17-8-2009 10730500@unknown@formal@none@1@S@There are 33,400 Russian speakers in Finland, amounting to 0.6% of the population.@@@@1@13@@danf@17-8-2009 10730510@unknown@formal@none@1@S@5000 (0.1%) of them are late 19th century and 20th century immigrants, and the rest are recent immigrants, who have arrived in the 90's and later.@@@@1@26@@danf@17-8-2009 10730520@unknown@formal@none@1@S@In the twentieth century, Russian was widely taught in the schools of the members of the old [[Warsaw Pact]] and in other [[Communist state|countries]] that used to be allies of the USSR.@@@@1@32@@danf@17-8-2009 10730530@unknown@formal@none@1@S@In particular, these countries include [[Poland]], [[Bulgaria]], the [[Czech Republic]], [[Slovakia]], [[Hungary]], [[Romania]], [[Albania]] and [[Cuba]].@@@@1@16@@danf@17-8-2009 10730540@unknown@formal@none@1@S@However, younger generations are usually not fluent in it, because Russian is no longer mandatory in the school system.@@@@1@19@@danf@17-8-2009 10730550@unknown@formal@none@1@S@It is currently the most widely-taught foreign language in [[Mongolia]].@@@@1@10@@danf@17-8-2009 10730560@unknown@formal@none@1@S@Russian is also spoken in [[Israel]] by at least 750,000 ethnic [[Jew]]ish immigrants from the former [[Soviet Union]] (1999 census).@@@@1@20@@danf@17-8-2009 10730570@unknown@formal@none@1@S@The Israeli [[Mass media|press]] and [[website]]s regularly publish material in Russian.@@@@1@11@@danf@17-8-2009 10730580@unknown@formal@none@1@S@Sizable Russian-speaking communities also exist in [[North America]], especially in large urban centers of the [[United States|U.S.]] and [[Canada]] such as [[New York City]], [[Philadelphia]], [[Boston, Massachusetts|Boston]], [[Los Angeles, California|Los Angeles]], [[San Francisco]], [[Seattle]], [[Toronto]], [[Baltimore]], [[Miami, Florida|Miami]], [[Chicago]], [[Denver]], and the [[Cleveland, Ohio|Cleveland]] suburb of [[Richmond Heights, Ohio|Richmond Heights]].@@@@1@50@@danf@17-8-2009 10730590@unknown@formal@none@1@S@In the former two, Russian-speaking groups total over half a million.@@@@1@11@@danf@17-8-2009 10730600@unknown@formal@none@1@S@In a number of locations they issue their own newspapers, and live in their self-sufficient neighborhoods (especially the generation of immigrants who started arriving in the early sixties).@@@@1@28@@danf@17-8-2009 10730610@unknown@formal@none@1@S@Only about a quarter of them are ethnic Russians, however.@@@@1@10@@danf@17-8-2009 10730620@unknown@formal@none@1@S@Before the [[dissolution of the Soviet Union]], the overwhelming majority of [[Russophone]]s in North America were Russian-speaking [[Jews]].@@@@1@18@@danf@17-8-2009 10730630@unknown@formal@none@1@S@Afterwards the influx from the countries of the former [[Soviet Union]] changed the statistics somewhat.@@@@1@15@@danf@17-8-2009 10730640@unknown@formal@none@1@S@According to the [[United States 2000 Census]], Russian is the primary language spoken in the homes of over 700,000 individuals living in the United States.@@@@1@25@@danf@17-8-2009 10730650@unknown@formal@none@1@S@Significant Russian-speaking groups also exist in [[Western Europe]].@@@@1@8@@danf@17-8-2009 10730660@unknown@formal@none@1@S@These have been fed by several waves of immigrants since the beginning of the twentieth century, each with its own flavor of language.@@@@1@23@@danf@17-8-2009 10730670@unknown@formal@none@1@S@[[Germany]], the [[United Kingdom]], [[Spain]], [[France]], [[Italy]], [[Belgium]], [[Greece]], [[Brazil]], [[Norway]], [[Austria]], and [[Turkey]] have significant Russian-speaking communities totaling 3 million people.@@@@1@22@@danf@17-8-2009 10730680@unknown@formal@none@1@S@Two thirds of them are actually Russian-speaking descendants of [[German people|Germans]], [[Greeks]], [[Jews]], [[Armenians]], or [[Ukrainians]] who either repatriated after the [[USSR]] collapsed or are just looking for temporary employment.@@@@1@30@@danf@17-8-2009 10730690@unknown@formal@none@1@S@Recent estimates of the total number of speakers of Russian:@@@@1@10@@danf@17-8-2009 10730700@unknown@formal@none@1@S@===Official status===@@@@1@2@@danf@17-8-2009 10730710@unknown@formal@none@1@S@Russian is the official language of [[Russia]].@@@@1@7@@danf@17-8-2009 10730720@unknown@formal@none@1@S@It is also an official language of [[Belarus]], [[Kazakhstan]], [[Kyrgyzstan]], an unofficial but widely spoken language in [[Ukraine]] and the de facto official language of the [[List of unrecognized countries|unrecognized]] of [[Transnistria]], [[South Ossetia]] and [[Abkhazia]].@@@@1@36@@danf@17-8-2009 10730730@unknown@formal@none@1@S@Russian is one of the [[United Nations#Languages|six official languages]] of the [[United Nations]].@@@@1@13@@danf@17-8-2009 10730740@unknown@formal@none@1@S@Education in Russian is still a popular choice for both Russian as a second language (RSL) and native speakers in Russia as well as many of the former Soviet republics.@@@@1@30@@danf@17-8-2009 10730750@unknown@formal@none@1@S@97% of the public school students of Russia, 75% in Belarus, 41% in Kazakhstan, 25% in [[Ukraine]], 23% in Kyrgyzstan, 21% in [[Moldova]], 7% in [[Azerbaijan]], 5% in [[Georgia (country)|Georgia]] and 2% in [[Armenia]] and [[Tajikistan]] receive their education only or mostly in Russian.@@@@1@44@@danf@17-8-2009 10730760@unknown@formal@none@1@S@Although the corresponding percentage of ethnic Russians is 78% in [[Russia]], 10% in [[Belarus]], 26% in [[Kazakhstan]], 17% in [[Ukraine]], 9% in [[Kyrgyzstan]], 6% in [[Republic of Moldova|Moldova]], 2% in [[Azerbaijan]], 1.5% in [[Georgia (country)|Georgia]] and less than 1% in both [[Armenia]] and [[Tajikistan]].@@@@1@44@@danf@17-8-2009 10730770@unknown@formal@none@1@S@Russian-language schooling is also available in Latvia, Estonia and Lithuania, but due to education reforms, a number of subjects taught in Russian are reduced at the high school level.@@@@1@29@@danf@17-8-2009 10730780@unknown@formal@none@1@S@The language has a co-official status alongside [[Moldovan language|Moldovan]] in the autonomies of [[Gagauzia]] and [[Transnistria]] in [[Moldova]], and in seven [[Romania]]n [[Commune in Romania|communes]] in [[Tulcea County|Tulcea]] and [[Constanţa County|Constanţa]] counties.@@@@1@32@@danf@17-8-2009 10730790@unknown@formal@none@1@S@In these localities, Russian-speaking [[Lipovans]], who are a recognized ethnic minority, make up more than 20% of the population.@@@@1@19@@danf@17-8-2009 10730800@unknown@formal@none@1@S@Thus, according to Romania's minority rights law, education, signage, and access to public administration and the justice system are provided in Russian alongside Romanian.@@@@1@24@@danf@17-8-2009 10730810@unknown@formal@none@1@S@In the [[Crimea|Autonomous Republic of Crimea]] in Ukraine, Russian is an officially recognized language alongside with [[Crimean Tatar language|Crimean Tatar]], but in reality, is the only language used by the government, thus being a ''[[de facto]]'' official language.@@@@1@38@@danf@17-8-2009 10730820@unknown@formal@none@1@S@===Dialects===@@@@1@1@@danf@17-8-2009 10730830@unknown@formal@none@1@S@Despite leveling after 1900, especially in matters of vocabulary, a number of dialects exist in Russia.@@@@1@16@@danf@17-8-2009 10730840@unknown@formal@none@1@S@Some linguists divide the dialects of the Russian language into two primary regional groupings, "Northern" and "Southern", with [[Moscow]] lying on the zone of transition between the two.@@@@1@28@@danf@17-8-2009 10730850@unknown@formal@none@1@S@Others divide the language into three groupings, Northern, Central and Southern, with Moscow lying in the Central region.@@@@1@18@@danf@17-8-2009 10730860@unknown@formal@none@1@S@[[Dialectology]] within Russia recognizes dozens of smaller-scale variants.@@@@1@8@@danf@17-8-2009 10730870@unknown@formal@none@1@S@The dialects often show distinct and non-standard features of pronunciation and intonation, vocabulary, and grammar.@@@@1@15@@danf@17-8-2009 10730880@unknown@formal@none@1@S@Some of these are relics of ancient usage now completely discarded by the standard language.@@@@1@15@@danf@17-8-2009 10730890@unknown@formal@none@1@S@The [[northern Russian dialects]] and those spoken along the [[Volga River]] typically pronounce unstressed {{IPA|/o/}} clearly (the phenomenon called [[vowel reduction in Russian#Back vowels|okanye]]/оканье).@@@@1@24@@danf@17-8-2009 10730900@unknown@formal@none@1@S@East of Moscow, particularly in [[Ryazan Region]], unstressed {{IPA|/e/}} and {{IPA|/a/}} following [[palatalization|palatalized]] consonants and preceding a stressed syllable are not reduced to {{IPA|[ɪ]}} (like in the Moscow dialect), being instead pronounced as {{IPA|/a/}} in such positions (e.g. несл'''и''' is pronounced as {{IPA|[nʲasˈlʲi]}}, not as {{IPA|[nʲɪsˈlʲi]}}) - this is called [[yakanye]]/ яканье; many southern dialects have a palatalized final {{IPA|/tʲ/}} in 3rd person forms of verbs (this is unpalatalized in the standard dialect) and a fricative {{IPA|[ɣ]}} where the standard dialect has {{IPA|[g]}}.@@@@1@83@@danf@17-8-2009 10730910@unknown@formal@none@1@S@However, in certain areas south of Moscow, e.g. in and around [[Tula, Russia|Tula]], {{IPA|/g/}} is pronounced as in the Moscow and northern dialects unless it precedes a voiceless plosive or a pause.@@@@1@32@@danf@17-8-2009 10730920@unknown@formal@none@1@S@In this position {{IPA|/g/}} is lenited and devoiced to the fricative {{IPA|[x]}}, e.g. друг {{IPA|[drux]}} (in Moscow's dialect, only Бог {{IPA|[box]}}, лёгкий {{IPA|[lʲɵxʲkʲɪj]}}, мягкий {{IPA|[ˈmʲæxʲkʲɪj]}} and some derivatives follow this rule).@@@@1@31@@danf@17-8-2009 10730930@unknown@formal@none@1@S@Some of these features (e.g. a [[debuccalization|debuccalized]] or [[lenition|lenited]] {{IPA|/g/}} and palatalized final {{IPA|/tʲ/}} in 3rd person forms of verbs) are also present in modern [[Ukrainian language|Ukrainian]], indicating either a linguistic continuum or strong influence one way or the other.@@@@1@40@@danf@17-8-2009 10730940@unknown@formal@none@1@S@The city of [[Veliky Novgorod]] has historically displayed a feature called chokanye/tsokanye (чоканье/цоканье), where {{IPA|/ʨ/}} and {{IPA|/ʦ/}} were confused (this is thought to be due to influence from [[Finnish language|Finnish]], which doesn't distinguish these sounds).@@@@1@35@@danf@17-8-2009 10730950@unknown@formal@none@1@S@So, '''ц'''апля ("heron") has been recorded as 'чапля'.@@@@1@8@@danf@17-8-2009 10730960@unknown@formal@none@1@S@Also, the second palatalization of [[Velar consonant|velar]]s did not occur there, so the so-called '''ě²''' (from the Proto-Slavonic diphthong *ai) did not cause {{IPA|/k, g, x/}} to shift to {{IPA|/ʦ, ʣ, s/}}; therefore where [[Standard Russian]] has '''ц'''епь ("chain"), the form '''к'''епь {{IPA|[kʲepʲ]}} is attested in earlier texts.@@@@1@48@@danf@17-8-2009 10730970@unknown@formal@none@1@S@Among the first to study Russian dialects was [[Mikhail Lomonosov|Lomonosov]] in the eighteenth century.@@@@1@14@@danf@17-8-2009 10730980@unknown@formal@none@1@S@In the nineteenth, [[Vladimir Dal]] compiled the first dictionary that included dialectal vocabulary.@@@@1@13@@danf@17-8-2009 10730990@unknown@formal@none@1@S@Detailed mapping of Russian dialects began at the turn of the twentieth century.@@@@1@13@@danf@17-8-2009 10731000@unknown@formal@none@1@S@In modern times, the monumental ''Dialectological Atlas of the Russian Language'' (''Диалектологический атлас русского языка'' {{IPA|[dʲɪɐˌlʲɛktəlɐˈgʲiʨɪskʲɪj ˈatləs ˈruskəvə jɪzɨˈka]}}), was published in 3 folio volumes 1986–1989, after four decades of preparatory work.@@@@1@32@@danf@17-8-2009 10731010@unknown@formal@none@1@S@The ''standard language'' is based on (but not identical to) the Moscow dialect.@@@@1@13@@danf@17-8-2009 10731020@unknown@formal@none@1@S@===Derived languages===@@@@1@2@@danf@17-8-2009 10731030@unknown@formal@none@1@S@* [[Balachka]] a dialect, spoken primarily by [[Cossacks]], in the regions of Don, [[Kuban]] and [[Terek]].@@@@1@16@@danf@17-8-2009 10731040@unknown@formal@none@1@S@* [[Fenya]], a criminal [[argot]] of ancient origin, with Russian grammar, but with distinct vocabulary.@@@@1@15@@danf@17-8-2009 10731050@unknown@formal@none@1@S@* [[Nadsat]], the fictional language spoken in '[[A Clockwork Orange]]' uses a lot of Russian words and Russian slang.@@@@1@19@@danf@17-8-2009 10731060@unknown@formal@none@1@S@* [[Surzhyk]] is a language with Russian and Ukrainian features, spoken in some areas of Ukraine@@@@1@16@@danf@17-8-2009 10731070@unknown@formal@none@1@S@* [[Trasianka]] is a language with Russian and Belarusian features used by a large portion of the rural population in [[Belarus]].@@@@1@21@@danf@17-8-2009 10731080@unknown@formal@none@1@S@* [[Quelia]], a pseudo pidgin of German and Russian.@@@@1@9@@danf@17-8-2009 10731090@unknown@formal@none@1@S@* [[Runglish]], Russian-English pidgin.@@@@1@4@@danf@17-8-2009 10731100@unknown@formal@none@1@S@This word is also used by English speakers to describe the way in which Russians attempt to speak English using Russian morphology and/or syntax.@@@@1@24@@danf@17-8-2009 10731110@unknown@formal@none@1@S@* [[Russenorsk language|Russenorsk]] is an extinct [[pidgin]] language with mostly Russian vocabulary and mostly [[Norwegian language|Norwegian]] grammar, used for communication between [[Russians]] and [[Norway|Norwegian]] traders in the Pomor trade in [[Finnmark]] and the [[Kola Peninsula]].@@@@1@35@@danf@17-8-2009 10731120@unknown@formal@none@1@S@==Writing system==@@@@1@2@@danf@17-8-2009 10731130@unknown@formal@none@1@S@===Alphabet===@@@@1@1@@danf@17-8-2009 10731140@unknown@formal@none@1@S@Russian is written using a modified version of the [[Cyrillic alphabet|Cyrillic (кириллица)]] alphabet.@@@@1@13@@danf@17-8-2009 10731150@unknown@formal@none@1@S@The Russian alphabet consists of 33 letters.@@@@1@7@@danf@17-8-2009 10731160@unknown@formal@none@1@S@The following table gives their upper case forms, along with [[help:IPA|IPA]] values for each letter's typical sound:@@@@1@17@@danf@17-8-2009 10731170@unknown@formal@none@1@S@Older letters of the Russian alphabet include <>, which merged to <е> ({{IPA|/e/}}); <і> and <>, which both merged to <и>({{IPA|/i/}}); <>, which merged to <ф> ({{IPA|/f/}}); and <>, which merged to <я> ({{IPA|/ja/}} or {{IPA|/ʲa/}}).@@@@1@36@@danf@17-8-2009 10731180@unknown@formal@none@1@S@While these older letters have been abandoned at one time or another, they may be used in this and related articles.@@@@1@21@@danf@17-8-2009 10731190@unknown@formal@none@1@S@The [[yer]]s <ъ> and <ь> originally indicated the pronunciation of ''ultra-short'' or ''reduced'' {{IPA|/ŭ/}}, {{IPA|/ĭ/}}.@@@@1@15@@danf@17-8-2009 10731200@unknown@formal@none@1@S@The Russian alphabet has many systems of [[character encoding]].@@@@1@9@@danf@17-8-2009 10731210@unknown@formal@none@1@S@[[KOI8-R]] was designed by the government and was intended to serve as the standard encoding.@@@@1@15@@danf@17-8-2009 10731220@unknown@formal@none@1@S@This encoding is still used in UNIX-like operating systems.@@@@1@9@@danf@17-8-2009 10731230@unknown@formal@none@1@S@Nevertheless, the spread of [[MS-DOS]] and [[Microsoft Windows]] created chaos and ended by establishing different encodings as de-facto standards.@@@@1@19@@danf@17-8-2009 10731240@unknown@formal@none@1@S@For communication purposes, a number of conversion applications were developed.@@@@1@10@@danf@17-8-2009 10731245@unknown@formal@none@1@S@"[[iconv]]" is an example that is supported by most versions of [[Linux]], [[Macintosh]] and some other [[operating system]]s.@@@@1@18@@danf@17-8-2009 10731250@unknown@formal@none@1@S@Most implementations (especially old ones) of the character encoding for the Russian language are aimed at simultaneous use of English and Russian characters only and do not include support for any other language.@@@@1@33@@danf@17-8-2009 10731260@unknown@formal@none@1@S@Certain hopes for a unification of the character encoding for the Russian alphabet are related to the [[Unicode|Unicode standard]], specifically designed for peaceful coexistence of various languages, including even [[dead language]]s.@@@@1@31@@danf@17-8-2009 10731270@unknown@formal@none@1@S@[[Unicode]] also supports the letters of the [[Early Cyrillic alphabet]], which have many similarities with the [[Greek alphabet]].@@@@1@18@@danf@17-8-2009 10731280@unknown@formal@none@1@S@===Orthography===@@@@1@1@@danf@17-8-2009 10731290@unknown@formal@none@1@S@Russian spelling is reasonably phonemic in practice.@@@@1@7@@danf@17-8-2009 10731300@unknown@formal@none@1@S@It is in fact a balance among phonemics, morphology, etymology, and grammar; and, like that of most living languages, has its share of inconsistencies and controversial points.@@@@1@27@@danf@17-8-2009 10731310@unknown@formal@none@1@S@A number of rigid [[spelling rule]]s introduced between the 1880s and 1910s have been responsible for the latter whilst trying to eliminate the former.@@@@1@24@@danf@17-8-2009 10731320@unknown@formal@none@1@S@The current spelling follows the major reform of 1918, and the final codification of 1956.@@@@1@15@@danf@17-8-2009 10731330@unknown@formal@none@1@S@An update proposed in the late 1990s has met a hostile reception, and has not been formally adopted.@@@@1@18@@danf@17-8-2009 10731340@unknown@formal@none@1@S@The punctuation, originally based on Byzantine Greek, was in the seventeenth and eighteenth centuries reformulated on the French and German models.@@@@1@21@@danf@17-8-2009 10731350@unknown@formal@none@1@S@==Sounds==@@@@1@1@@danf@17-8-2009 10731360@unknown@formal@none@1@S@The phonological system of Russian is inherited from [[Common Slavonic]], but underwent considerable modification in the early historical period, before being largely settled by about 1400.@@@@1@26@@danf@17-8-2009 10731370@unknown@formal@none@1@S@The language possesses five vowels, which are written with different letters depending on whether or not the preceding consonant is [[palatalization|palatalized]].@@@@1@21@@danf@17-8-2009 10731380@unknown@formal@none@1@S@The consonants typically come in plain vs. palatalized pairs, which are traditionally called ''hard'' and ''soft.''@@@@1@16@@danf@17-8-2009 10731390@unknown@formal@none@1@S@(The ''hard'' consonants are often [[velarization|velarized]], especially before back vowels, although in some dialects the velarization is limited to hard {{IPA|/l/}}).@@@@1@21@@danf@17-8-2009 10731400@unknown@formal@none@1@S@The standard language, based on the Moscow dialect, possesses heavy stress and moderate variation in pitch.@@@@1@16@@danf@17-8-2009 10731410@unknown@formal@none@1@S@Stressed vowels are somewhat lengthened, while unstressed vowels tend to be reduced to near-close vowels or an unclear [[schwa]].@@@@1@19@@danf@17-8-2009 10731420@unknown@formal@none@1@S@(See also: [[vowel reduction in Russian]].)@@@@1@6@@danf@17-8-2009 10731430@unknown@formal@none@1@S@The Russian [[syllable]] structure can be quite complex with both initial and final consonant clusters of up to 4 consecutive sounds.@@@@1@21@@danf@17-8-2009 10731440@unknown@formal@none@1@S@Using a formula with V standing for the nucleus (vowel) and C for each consonant the structure can be described as follows:@@@@1@22@@danf@17-8-2009 10731450@unknown@formal@none@1@S@(C)(C)(C)(C)V(C)(C)(C)(C)@@@@1@1@@danf@17-8-2009 10731460@unknown@formal@none@1@S@Clusters of four consonants are not very common, however, especially within a morpheme.@@@@1@13@@danf@17-8-2009 10731470@unknown@formal@none@1@S@===Consonants===@@@@1@1@@danf@17-8-2009 10731480@unknown@formal@none@1@S@Russian is notable for its distinction based on [[palatalization]] of most of the consonants.@@@@1@14@@danf@17-8-2009 10731490@unknown@formal@none@1@S@While {{IPA|/k/, /g/, /x/}} do have palatalized [[allophone]]s {{IPA|[kʲ, gʲ, xʲ]}}, only {{IPA|/kʲ/}} might be considered a phoneme, though it is marginal and generally not considered distinctive (the only native [[minimal pair]] which argues for {{IPA|/kʲ/}} to be a separate phoneme is "это ткёт"/"этот кот").@@@@1@45@@danf@17-8-2009 10731500@unknown@formal@none@1@S@Palatalization means that the center of the tongue is raised during and after the articulation of the consonant.@@@@1@18@@danf@17-8-2009 10731510@unknown@formal@none@1@S@In the case of {{IPA|/tʲ/ and /dʲ/}}, the tongue is raised enough to produce slight frication (affricate sounds).@@@@1@18@@danf@17-8-2009 10731520@unknown@formal@none@1@S@These sounds: {{IPA|/t, d, ʦ, s, z, n and rʲ/}} are [[dental consonant|dental]], that is pronounced with the tip of the tongue against the teeth rather than against the [[alveolar ridge]].@@@@1@31@@danf@17-8-2009 10731530@unknown@formal@none@1@S@==Grammar==@@@@1@1@@danf@17-8-2009 10731540@unknown@formal@none@1@S@Russian has preserved an [[Indo-European languages|Indo-European]] [[Synthetic language|synthetic]]-[[inflection]]al structure, although considerable leveling has taken place.@@@@1@15@@danf@17-8-2009 10731550@unknown@formal@none@1@S@Russian grammar encompasses@@@@1@3@@danf@17-8-2009 10731560@unknown@formal@none@1@S@* a highly [[Synthetic language|synthetic]] '''morphology'''@@@@1@6@@danf@17-8-2009 10731570@unknown@formal@none@1@S@* a '''syntax''' that, for the literary language, is the conscious fusion of three elements:@@@@1@15@@danf@17-8-2009 10731580@unknown@formal@none@1@S@** a polished [[vernacular]] foundation;@@@@1@5@@danf@17-8-2009 10731590@unknown@formal@none@1@S@** a [[Church Slavonic language|Church Slavonic]] inheritance;@@@@1@7@@danf@17-8-2009 10731600@unknown@formal@none@1@S@** a [[Western Europe]]an style.@@@@1@5@@danf@17-8-2009 10731610@unknown@formal@none@1@S@The spoken language has been influenced by the literary one, but continues to preserve characteristic forms.@@@@1@16@@danf@17-8-2009 10731620@unknown@formal@none@1@S@The dialects show various non-standard grammatical features, some of which are archaisms or descendants of old forms since discarded by the literary language.@@@@1@23@@danf@17-8-2009 10731630@unknown@formal@none@1@S@==Vocabulary==@@@@1@1@@danf@17-8-2009 10731640@unknown@formal@none@1@S@See [[History of the Russian language]] for an account of the successive foreign influences on the Russian language.@@@@1@18@@danf@17-8-2009 10731650@unknown@formal@none@1@S@The total number of words in Russian is difficult to reckon because of the ability to agglutinate and create manifold compounds, diminutives, etc. (see [[Russian grammar#Word Formation|Word Formation]] under [[Russian grammar]]).@@@@1@31@@danf@17-8-2009 10731660@unknown@formal@none@1@S@The number of listed words or entries in some of the major dictionaries published during the last two centuries, and the total vocabulary of [[Pushkin]] (who is credited with greatly augmenting and codifying literary Russian), are as follows:@@@@1@38@@danf@17-8-2009 10731670@unknown@formal@none@1@S@(As a historical aside, [[Vladimir Ivanovich Dal|Dahl]] was, in the second half of the nineteenth century, still insisting that the proper spelling of the adjective '''русский''', which was at that time applied uniformly to all the Orthodox Eastern Slavic subjects of the Empire, as well as to its one official language, be spelled '''руский''' with one s, in accordance with ancient tradition and what he termed the "spirit of the language".@@@@1@71@@danf@17-8-2009 10731680@unknown@formal@none@1@S@He was contradicted by the philologist Grot, who distinctly heard the s lengthened or doubled).@@@@1@15@@danf@17-8-2009 10731690@unknown@formal@none@1@S@=== Proverbs and sayings ===@@@@1@5@@danf@17-8-2009 10731700@unknown@formal@none@1@S@The Russian language is replete with many hundreds of proverbs ('''пословица''' {{IPA|[pɐˈslo.vʲɪ.ʦə]}}) and sayings ('''поговоркa''' {{IPA|[pə.gɐˈvo.rkə]}}).@@@@1@16@@danf@17-8-2009 10731710@unknown@formal@none@1@S@These were already tabulated by the seventeenth century, and collected and studied in the nineteenth and twentieth, with the folk-tales being an especially fertile source.@@@@1@25@@danf@17-8-2009 10731720@unknown@formal@none@1@S@==History and examples==@@@@1@3@@danf@17-8-2009 10731730@unknown@formal@none@1@S@The history of Russian language may be divided into the following periods.@@@@1@12@@danf@17-8-2009 10731740@unknown@formal@none@1@S@* [[History of the Russian language#Kievan period and feudal breakup|Kievan period and feudal breakup]]@@@@1@14@@danf@17-8-2009 10731750@unknown@formal@none@1@S@* [[History of the Russian language#The Tatar yoke and the Grand Duchy of Lithuania|The Tatar yoke and the Grand Duchy of Lithuania]]@@@@1@22@@danf@17-8-2009 10731760@unknown@formal@none@1@S@* [[History of the Russian language#The Moscovite period (15th–17th centuries)|The Moscovite period (15th–17th centuries)]]@@@@1@14@@danf@17-8-2009 10731770@unknown@formal@none@1@S@* [[History of the Russian language#Empire (18th–19th centuries)|Empire (18th–19th centuries)]]@@@@1@10@@danf@17-8-2009 10731780@unknown@formal@none@1@S@* [[History of the Russian language#Soviet period and beyond (20th century)|Soviet period and beyond (20th century)]]@@@@1@16@@danf@17-8-2009 10731790@unknown@formal@none@1@S@Judging by the historical records, by approximately 1000 AD the predominant ethnic group over much of modern European [[Russia]], [[Ukraine]], and [[Belarus]] was the Eastern branch of the [[Slavic peoples|Slavs]], speaking a closely related group of dialects.@@@@1@37@@danf@17-8-2009 10731800@unknown@formal@none@1@S@The political unification of this region into [[Kievan Rus']] in about 880, from which modern Russia, Ukraine and Belarus trace their origins, established [[Old East Slavic]] as a literary and commercial language.@@@@1@32@@danf@17-8-2009 10731810@unknown@formal@none@1@S@It was soon followed by the adoption of [[Christianity]] in 988 and the introduction of the South Slavic [[Old Church Slavonic]] as the liturgical and official language.@@@@1@27@@danf@17-8-2009 10731820@unknown@formal@none@1@S@Borrowings and [[calque]]s from Byzantine [[Greek language|Greek]] began to enter the [[Old East Slavic]] and spoken dialects at this time, which in their turn modified the [[Old Church Slavonic]] as well.@@@@1@31@@danf@17-8-2009 10731830@unknown@formal@none@1@S@Dialectal differentiation accelerated after the breakup of [[Kievan Rus]] in approximately 1100.@@@@1@12@@danf@17-8-2009 10731840@unknown@formal@none@1@S@On the territories of modern [[Belarus]] and [[Ukraine]] emerged [[Ruthenian language|Ruthenian]] and in modern [[Russia]] [[History of the Russian language|medieval Russian]].@@@@1@21@@danf@17-8-2009 10731850@unknown@formal@none@1@S@They definitely became distinct in 13th century by the time of division of that land between the [[Grand Duchy of Lithuania]] on the west and independent Novgorod Feudal Republic plus small duchies which were vassals of the Tatars on the east.@@@@1@41@@danf@17-8-2009 10731860@unknown@formal@none@1@S@The official language in Moscow and Novgorod, and later, in the growing Moscow Rus’, was [[Church Slavonic]] which evolved from [[Old Church Slavonic]] and remained [[Diglossia|the literary language]] until the Petrine age, when its usage shrank drastically to biblical and liturgical texts.@@@@1@42@@danf@17-8-2009 10731870@unknown@formal@none@1@S@Russian developed under a strong influence of the Church Slavonic until the close of the seventeenth century; the influence reversed afterwards leading to corruption of liturgical texts.@@@@1@27@@danf@17-8-2009 10731880@unknown@formal@none@1@S@The political reforms of [[Peter I of Russia|Peter the Great]] were accompanied by a reform of the alphabet, and achieved their goal of secularization and Westernization.@@@@1@26@@danf@17-8-2009 10731890@unknown@formal@none@1@S@Blocks of specialized vocabulary were adopted from the languages of Western Europe.@@@@1@12@@danf@17-8-2009 10731900@unknown@formal@none@1@S@By 1800, a significant portion of the gentry spoke [[French language|French]], less often [[German language|German]], on an everyday basis.@@@@1@19@@danf@17-8-2009 10731910@unknown@formal@none@1@S@Many Russian novels of the 19th century, e.g. Lev Tolstoy’s "War and Peace", contain entire paragraphs and even pages in French with no translation given, with an assumption that educated readers won't need one.@@@@1@34@@danf@17-8-2009 10731920@unknown@formal@none@1@S@The modern literary language is usually considered to date from the time of [[Aleksandr Pushkin]] in the first third of the nineteenth century.@@@@1@23@@danf@17-8-2009 10731930@unknown@formal@none@1@S@Pushkin revolutionized Russian literature by rejecting archaic grammar and vocabulary (so called "высокий стиль" — "high style") in favor of grammar and vocabulary found in the spoken language of the time.@@@@1@31@@danf@17-8-2009 10731940@unknown@formal@none@1@S@Even modern readers of younger age may only experience slight difficulties understanding some words in Pushkin’s texts, since only few words used by Pushkin became archaic or changed meaning.@@@@1@29@@danf@17-8-2009 10731950@unknown@formal@none@1@S@On the other hand, many expressions used by Russian writers of the early 19th century, in particular Pushkin, [[Lermontov]], [[Gogol]], Griboiädov, became proverbs or sayings which can be frequently found even in the modern Russian colloquial speech.@@@@1@37@@danf@17-8-2009 10731960@unknown@formal@none@1@S@The political upheavals of the early twentieth century and the wholesale changes of political ideology gave written Russian its modern appearance after the spelling reform of 1918.@@@@1@27@@danf@17-8-2009 10731970@unknown@formal@none@1@S@Political circumstances and Soviet accomplishments in military, scientific, and technological matters (especially cosmonautics), gave Russian a world-wide prestige, especially during the middle third of the twentieth century.@@@@1@27@@danf@17-8-2009 10740010@unknown@formal@none@1@S@
Web search engine
@@@@1@3@@danf@17-8-2009 10740020@unknown@formal@none@1@S@A '''Web search engine''' is a [[search engine (computing)|search engine]] designed to search for information on the [[World Wide Web]].@@@@1@20@@danf@17-8-2009 10740030@unknown@formal@none@1@S@Information may consist of [[web page]]s, images and other types of files.@@@@1@12@@danf@17-8-2009 10740040@unknown@formal@none@1@S@Some search engines also mine data available in newsbooks, databases, or [[Web directory|open directories]].@@@@1@14@@danf@17-8-2009 10740050@unknown@formal@none@1@S@Unlike [[Web directories]], which are maintained by human editors, search engines operate algorithmically or are a mixture of [[algorithmic]] and human input.@@@@1@22@@danf@17-8-2009 10740060@unknown@formal@none@1@S@==History==@@@@1@1@@danf@17-8-2009 10740070@unknown@formal@none@1@S@Before there were search engines there was a complete list of all webservers.@@@@1@13@@danf@17-8-2009 10740080@unknown@formal@none@1@S@The list was edited by [[Tim Berners-Lee]] and hosted on the CERN webserver.@@@@1@13@@danf@17-8-2009 10740090@unknown@formal@none@1@S@One historical snapshot from 1992 remains.@@@@1@6@@danf@17-8-2009 10740100@unknown@formal@none@1@S@As more and more webservers went online the central list could not keep up.@@@@1@14@@danf@17-8-2009 10740110@unknown@formal@none@1@S@On the NCSA Site new servers were announced under the title "What's New!", but no complete listing existed any more.@@@@1@20@@danf@17-8-2009 10740120@unknown@formal@none@1@S@The very first tool used for searching on the (pre-web) Internet was [[Archie search engine|Archie]].@@@@1@15@@danf@17-8-2009 10740130@unknown@formal@none@1@S@The name stands for "archive" without the "v".@@@@1@8@@danf@17-8-2009 10740140@unknown@formal@none@1@S@It was created in 1990 by [[Alan Emtage]], a student at [[McGill University]] in Montreal.@@@@1@15@@danf@17-8-2009 10740150@unknown@formal@none@1@S@The program downloaded the directory listings of all the files located on public anonymous FTP ([[File Transfer Protocol]]) sites, creating a searchable database of file names; however, Archie did not index the contents of these sites.@@@@1@36@@danf@17-8-2009 10740160@unknown@formal@none@1@S@The rise of [[Gopher (protocol)|Gopher]] (created in 1991 by [[Mark McCahill]] at the [[University of Minnesota]]) led to two new search programs, [[Veronica (computer)|Veronica]] and [[Jughead (computer)|Jughead]].@@@@1@27@@danf@17-8-2009 10740170@unknown@formal@none@1@S@Like Archie, they searched the file names and titles stored in Gopher index systems.@@@@1@14@@danf@17-8-2009 10740180@unknown@formal@none@1@S@Veronica ('''V'''ery '''E'''asy '''R'''odent-'''O'''riented '''N'''et-wide '''I'''ndex to '''C'''omputerized '''A'''rchives) provided a keyword search of most Gopher menu titles in the entire Gopher listings.@@@@1@23@@danf@17-8-2009 10740190@unknown@formal@none@1@S@Jughead ('''J'''onzy's '''U'''niversal '''G'''opher '''H'''ierarchy '''E'''xcavation '''A'''nd '''D'''isplay) was a tool for obtaining menu information from specific Gopher servers.@@@@1@19@@danf@17-8-2009 10740200@unknown@formal@none@1@S@While the name of the search engine "[[Archie search engine|Archie]]" was not a reference to the [[Archie Comics|Archie comic book]] series, "[[Veronica Lodge|Veronica]]" and "[[Jughead Jones|Jughead]]" are characters in the series, thus referencing their predecessor.@@@@1@35@@danf@17-8-2009 10740210@unknown@formal@none@1@S@The first Web search engine was Wandex, a now-defunct index collected by the [[World Wide Web Wanderer]], a [[web crawler]] developed by Matthew Gray at [[Massachusetts Institute of Technology|MIT]] in 1993.@@@@1@31@@danf@17-8-2009 10740220@unknown@formal@none@1@S@Another very early search engine, [[Aliweb]], also appeared in 1993.@@@@1@10@@danf@17-8-2009 10740230@unknown@formal@none@1@S@[[JumpStation]] (released in early 1994) used a crawler to find web pages for searching, but search was limited to the title of web pages only.@@@@1@25@@danf@17-8-2009 10740240@unknown@formal@none@1@S@One of the first "full text" crawler-based search engines was [[WebCrawler]], which came out in 1994.@@@@1@16@@danf@17-8-2009 10740250@unknown@formal@none@1@S@Unlike its predecessors, it let users search for any word in any webpage, which became the standard for all major search engines since.@@@@1@23@@danf@17-8-2009 10740260@unknown@formal@none@1@S@It was also the first one to be widely known by the public.@@@@1@13@@danf@17-8-2009 10740270@unknown@formal@none@1@S@Also in 1994 [[Lycos]] (which started at [[Carnegie Mellon University]]) was launched, and became a major commercial endeavor.@@@@1@18@@danf@17-8-2009 10740280@unknown@formal@none@1@S@Soon after, many search engines appeared and vied for popularity.@@@@1@10@@danf@17-8-2009 10740290@unknown@formal@none@1@S@These included [[Magellan]], [[Excite]], [[Infoseek]], [[Inktomi]], [[Northern Light Group|Northern Light]], and [[AltaVista]].@@@@1@12@@danf@17-8-2009 10740300@unknown@formal@none@1@S@[[Yahoo!]] was among the most popular ways for people to find web pages of interest, but its search function operated on its [[web directory]], rather than full-text copies of web pages.@@@@1@31@@danf@17-8-2009 10740310@unknown@formal@none@1@S@Information seekers could also browse the directory instead of doing a keyword-based search.@@@@1@13@@danf@17-8-2009 10740320@unknown@formal@none@1@S@In 1996, [[Netscape]] was looking to give a single search engine an exclusive deal to be their featured search engine.@@@@1@20@@danf@17-8-2009 10740330@unknown@formal@none@1@S@There was so much interest that instead a deal was struck with Netscape by 5 of the major search engines, where for $5Million per year each search engine would be in a rotation on the Netscape search engine page.@@@@1@39@@danf@17-8-2009 10740340@unknown@formal@none@1@S@These five engines were: [[Yahoo!]], [[Magellan]], [[Lycos]], [[Infoseek]] and [[Excite]].@@@@1@10@@danf@17-8-2009 10740350@unknown@formal@none@1@S@Search engines were also known as some of the brightest stars in the Internet investing frenzy that occurred in the late 1990s.@@@@1@22@@danf@17-8-2009 10740360@unknown@formal@none@1@S@Several companies entered the market spectacularly, receiving record gains during their [[initial public offering]]s.@@@@1@14@@danf@17-8-2009 10740370@unknown@formal@none@1@S@Some have taken down their public search engine, and are marketing enterprise-only editions, such as Northern Light.@@@@1@17@@danf@17-8-2009 10740380@unknown@formal@none@1@S@Many search engine companies were caught up in the [[dot-com bubble]], a speculation-driven market boom that peaked in 1999 and ended in 2001.@@@@1@23@@danf@17-8-2009 10740390@unknown@formal@none@1@S@Around 2000, the [[Google Search|Google search engine]] rose to prominence.@@@@1@10@@danf@17-8-2009 10740400@unknown@formal@none@1@S@The company achieved better results for many searches with an innovation called [[PageRank]].@@@@1@13@@danf@17-8-2009 10740410@unknown@formal@none@1@S@This iterative algorithm ranks web pages based on the number and PageRank of other web sites and pages that link there, on the premise that good or desirable pages are linked to more than others.@@@@1@35@@danf@17-8-2009 10740420@unknown@formal@none@1@S@Google also maintained a minimalist interface to its search engine.@@@@1@10@@danf@17-8-2009 10740430@unknown@formal@none@1@S@In contrast, many of its competitors embedded a search engine in a [[web portal]].@@@@1@14@@danf@17-8-2009 10740440@unknown@formal@none@1@S@By 2000, Yahoo was providing search services based on [[Inktomi]]'s search engine.@@@@1@12@@danf@17-8-2009 10740450@unknown@formal@none@1@S@Yahoo! acquired [[Inktomi]] in 2002, and [[Overture]] (which owned [[AlltheWeb]] and [[AltaVista]]) in 2003.@@@@1@14@@danf@17-8-2009 10740460@unknown@formal@none@1@S@Yahoo! switched to Google's search engine until 2004, when it launched its own search engine based on the combined technologies of its acquisitions.@@@@1@23@@danf@17-8-2009 10740470@unknown@formal@none@1@S@Microsoft first launched MSN Search (since re-branded [[Live Search]]) in the fall of 1998 using search results from [[Inktomi]].@@@@1@19@@danf@17-8-2009 10740480@unknown@formal@none@1@S@In early 1999 the site began to display listings from [[Looksmart]] blended with results from [[Inktomi]] except for a short time in 1999 when results from [[AltaVista]] were used instead.@@@@1@30@@danf@17-8-2009 10740490@unknown@formal@none@1@S@In 2004, Microsoft began a transition to its own search technology, powered by its own [[web crawler]] (called [[msnbot]]).@@@@1@19@@danf@17-8-2009 10740500@unknown@formal@none@1@S@As of late 2007, Google was by far the most popular Web search engine worldwide.@@@@1@15@@danf@17-8-2009 10740510@unknown@formal@none@1@S@A number of country-specific search engine companies have become prominent; for example [[Baidu]] is the most popular search engine in the [[People's Republic of China]] and [[guruji.com]] in [[India]].@@@@1@29@@danf@17-8-2009 10740520@unknown@formal@none@1@S@==How Web search engines work==@@@@1@5@@danf@17-8-2009 10740530@unknown@formal@none@1@S@A search engine operates, in the following order@@@@1@8@@danf@17-8-2009 10740540@unknown@formal@none@1@S@# [[Web crawling]]@@@@1@3@@danf@17-8-2009 10740550@unknown@formal@none@1@S@# [[Index (search engine)|Indexing]]@@@@1@4@@danf@17-8-2009 10740560@unknown@formal@none@1@S@# [[Web search query|Searching]]@@@@1@4@@danf@17-8-2009 10740570@unknown@formal@none@1@S@Web search engines work by storing information about many web pages, which they retrieve from the WWW itself.@@@@1@18@@danf@17-8-2009 10740580@unknown@formal@none@1@S@These pages are retrieved by a [[Web crawler]] (sometimes also known as a spider) — an automated Web browser which follows every link it sees.@@@@1@25@@danf@17-8-2009 10740590@unknown@formal@none@1@S@Exclusions can be made by the use of [[robots.txt]].@@@@1@9@@danf@17-8-2009 10740600@unknown@formal@none@1@S@The contents of each page are then analyzed to determine how it should be [[Search engine indexing|indexed]] (for example, words are extracted from the titles, headings, or special fields called [[meta tags]]).@@@@1@32@@danf@17-8-2009 10740610@unknown@formal@none@1@S@Data about web pages are stored in an index database for use in later queries.@@@@1@15@@danf@17-8-2009 10740620@unknown@formal@none@1@S@Some search engines, such as [[Google]], store all or part of the source page (referred to as a [[web cache|cache]]) as well as information about the web pages, whereas others, such as [[AltaVista]], store every word of every page they find.@@@@1@41@@danf@17-8-2009 10740630@unknown@formal@none@1@S@This cached page always holds the actual search text since it is the one that was actually indexed, so it can be very useful when the content of the current page has been updated and the search terms are no longer in it.@@@@1@43@@danf@17-8-2009 10740640@unknown@formal@none@1@S@This problem might be considered to be a mild form of [[linkrot]], and Google's handling of it increases [[usability]] by satisfying [[user expectations]] that the search terms will be on the returned webpage.@@@@1@33@@danf@17-8-2009 10740650@unknown@formal@none@1@S@This satisfies the [[principle of least astonishment]] since the user normally expects the search terms to be on the returned pages.@@@@1@21@@danf@17-8-2009 10740660@unknown@formal@none@1@S@Increased search relevance makes these cached pages very useful, even beyond the fact that they may contain data that may no longer be available elsewhere.@@@@1@25@@danf@17-8-2009 10740670@unknown@formal@none@1@S@When a user enters a [[web search query|query]] into a search engine (typically by using [[Keyword (Internet search)|key word]]s), the engine examines its [[inverted index|index]] and provides a listing of best-matching web pages according to its criteria, usually with a short summary containing the document's title and sometimes parts of the text.@@@@1@52@@danf@17-8-2009 10740680@unknown@formal@none@1@S@Most search engines support the use of the [[boolean operators]] AND, OR and NOT to further specify the [[web search query|search query]].@@@@1@22@@danf@17-8-2009 10740690@unknown@formal@none@1@S@Some search engines provide an advanced feature called [[Proximity search (text)|proximity search]] which allows users to define the distance between keywords.@@@@1@21@@danf@17-8-2009 10740700@unknown@formal@none@1@S@The usefulness of a search engine depends on the [[relevance (information retrieval)|relevance]] of the '''result set''' it gives back.@@@@1@19@@danf@17-8-2009 10740710@unknown@formal@none@1@S@While there may be millions of webpages that include a particular word or phrase, some pages may be more relevant, popular, or authoritative than others.@@@@1@25@@danf@17-8-2009 10740720@unknown@formal@none@1@S@Most search engines employ methods to [[rank order|rank]] the results to provide the "best" results first.@@@@1@16@@danf@17-8-2009 10740730@unknown@formal@none@1@S@How a search engine decides which pages are the best matches, and what order the results should be shown in, varies widely from one engine to another.@@@@1@27@@danf@17-8-2009 10740740@unknown@formal@none@1@S@The methods also change over time as Internet usage changes and new techniques evolve.@@@@1@14@@danf@17-8-2009 10740750@unknown@formal@none@1@S@Most Web search engines are commercial ventures supported by [[advertising]] revenue and, as a result, some employ the controversial practice of allowing advertisers to pay money to have their listings ranked higher in search results.@@@@1@35@@danf@17-8-2009 10740760@unknown@formal@none@1@S@Those search engines which do not accept money for their search engine results make money by running search related ads alongside the regular search engine results.@@@@1@26@@danf@17-8-2009 10740770@unknown@formal@none@1@S@The search engines make money every time someone clicks on one of these ads.@@@@1@14@@danf@17-8-2009 10740780@unknown@formal@none@1@S@The vast majority of search engines are run by private companies using proprietary algorithms and closed databases, though [[List of search engines#Open source search engines|some]] are open source.@@@@1@28@@danf@17-8-2009 10740790@unknown@formal@none@1@S@Revenue in the web search portals industry is projected to grow in 2008 by 13.4 percent, with broadband connections expected to rise by 15.1 percent.@@@@1@25@@danf@17-8-2009 10740800@unknown@formal@none@1@S@Between 2008 and 2012, industry revenue is projected to rise by 56 percent as Internet penetration still has some way to go to reach full saturation in American households.@@@@1@29@@danf@17-8-2009 10740810@unknown@formal@none@1@S@Furthermore, broadband services are projected to account for an ever increasing share of domestic Internet users, rising to 118.7 million by 2012, with an increasing share accounted for by fiber-optic and high speed cable lines.@@@@1@35@@danf@17-8-2009 10750010@unknown@formal@none@1@S@
Semantics
@@@@1@1@@danf@17-8-2009 10750020@unknown@formal@none@1@S@'''Semantics''' is the study of meaning in communication.@@@@1@8@@danf@17-8-2009 10750030@unknown@formal@none@1@S@The word derives from [[Greek language|Greek]] ''σημαντικός'' (''semantikos''), "significant", from ''σημαίνω'' (''semaino''), "to signify, to indicate" and that from ''σήμα'' (''sema''), "sign, mark, token".@@@@1@24@@danf@17-8-2009 10750040@unknown@formal@none@1@S@In [[linguistics]] it is the study of interpretation of signs as used by [[agent]]s or [[community|communities]] within particular circumstances and contexts.@@@@1@21@@danf@17-8-2009 10750050@unknown@formal@none@1@S@It has related meanings in several other fields.@@@@1@8@@danf@17-8-2009 10750060@unknown@formal@none@1@S@Semanticists differ on what constitutes [[Meaning (linguistics)|meaning]] in an expression.@@@@1@10@@danf@17-8-2009 10750070@unknown@formal@none@1@S@For example, in the sentence, "John loves a bagel", the word ''bagel'' may refer to the object itself, which is its ''literal'' meaning or ''[[denotation]]'', but it may also refer to many other figurative associations, such as how it meets John's hunger, etc., which may be its ''[[connotation]]''.@@@@1@48@@danf@17-8-2009 10750080@unknown@formal@none@1@S@Traditionally, the [[formal semantic]] view restricts semantics to its literal meaning, and relegates all figurative associations to [[pragmatics]], but this distinction is increasingly difficult to defend.@@@@1@26@@danf@17-8-2009 10750090@unknown@formal@none@1@S@The degree to which a theorist subscribes to the literal-figurative distinction decreases as one moves from the [[formal semantic]], [[semiotic]], [[pragmatic]], to the [[cognitive semantic]] traditions.@@@@1@26@@danf@17-8-2009 10750100@unknown@formal@none@1@S@The word ''semantic'' in its modern sense is considered to have first appeared in [[French language|French]] as ''sémantique'' in [[Michel Bréal]]'s 1897 book, ''Essai de sémantique'.@@@@1@26@@danf@17-8-2009 10750110@unknown@formal@none@1@S@In [[International Scientific Vocabulary]] semantics is also called ''[[semasiology]]''.@@@@1@9@@danf@17-8-2009 10750120@unknown@formal@none@1@S@The discipline of Semantics is distinct from [[General semantics|Alfred Korzybski's General Semantics]], which is a system for looking at non-immediate, or abstract meanings.@@@@1@23@@danf@17-8-2009 10750130@unknown@formal@none@1@S@==Linguistics==@@@@1@1@@danf@17-8-2009 10750140@unknown@formal@none@1@S@In [[linguistics]], '''semantics''' is the subfield that is devoted to the study of meaning, as inherent at the levels of words, phrases, sentences, and even larger units of [[discourse]] (referred to as ''texts'').@@@@1@33@@danf@17-8-2009 10750150@unknown@formal@none@1@S@The basic area of study is the meaning of [[sign (semiotics)|sign]]s, and the study of relations between different linguistic units: [[homonym]]y, [[synonym]]y, [[antonym]]y, [[polysemy]], [[paronyms]], [[hypernym]]y, [[hyponym]]y, [[meronymy]], [[metonymy]], [[holonymy]], [[exocentric]]ity / [[endocentric]]ity, linguistic [[compound (linguistics)|compounds]].@@@@1@36@@danf@17-8-2009 10750160@unknown@formal@none@1@S@A key concern is how meaning attaches to larger chunks of text, possibly as a result of the composition from smaller units of meaning.@@@@1@24@@danf@17-8-2009 10750170@unknown@formal@none@1@S@Traditionally, semantics has included the study of connotative ''[[word sense|sense]]'' and denotative ''[[reference]]'', [[truth condition]]s, [[argument structure]], [[thematic role]]s, [[discourse analysis]], and the linkage of all of these to syntax.@@@@1@30@@danf@17-8-2009 10750180@unknown@formal@none@1@S@[[Formal semantics|Formal semanticists]] are concerned with the modeling of meaning in terms of the semantics of logic.@@@@1@17@@danf@17-8-2009 10750190@unknown@formal@none@1@S@Thus the sentence ''John loves a bagel'' above can be broken down into its constituents (signs), of which the unit ''loves'' may serve as both syntactic and semantic [[head (linguistics)|head]].@@@@1@30@@danf@17-8-2009 10750200@unknown@formal@none@1@S@In the late 1960s, [[Richard Montague]] proposed a system for defining semantic entries in the lexicon in terms of [[lambda calculus]].@@@@1@21@@danf@17-8-2009 10750210@unknown@formal@none@1@S@Thus, the syntactic [[parsing|parse]] of the sentence above would now indicate ''loves'' as the head, and its entry in the lexicon would point to the arguments as the agent, ''John'', and the object, ''bagel'', with a special role for the article "a" (which Montague called a quantifier).@@@@1@47@@danf@17-8-2009 10750220@unknown@formal@none@1@S@This resulted in the sentence being associated with the logical predicate ''loves (John, bagel)'', thus linking semantics to [[categorial grammar]] models of [[syntax]].@@@@1@23@@danf@17-8-2009 10750230@unknown@formal@none@1@S@The logical predicate thus obtained would be elaborated further, e.g. using truth theory models, which ultimately relate meanings to a set of [[Tarski]]ian universals, which may lie outside the logic.@@@@1@30@@danf@17-8-2009 10750240@unknown@formal@none@1@S@The notion of such meaning atoms or primitives are basic to the [[language of thought]] hypothesis from the 70s.@@@@1@19@@danf@17-8-2009 10750250@unknown@formal@none@1@S@Despite its elegance, [[Montague grammar]] was limited by the context-dependent variability in word sense, and led to several attempts at incorporating context, such as :@@@@1@25@@danf@17-8-2009 10750260@unknown@formal@none@1@S@*[[situation semantics]] ('80s): Truth-values are incomplete, they get assigned based on context@@@@1@12@@danf@17-8-2009 10750270@unknown@formal@none@1@S@*[[generative lexicon]] ('90s): categories (types) are incomplete, and get assigned based on context@@@@1@13@@danf@17-8-2009 10750280@unknown@formal@none@1@S@===The dynamic turn in semantics===@@@@1@5@@danf@17-8-2009 10750290@unknown@formal@none@1@S@In the [[Noam Chomsky|Chomskian]] tradition in linguistics there was no mechanism for the learning of semantic relations, and the [[Psychological nativism|nativist]] view considered all semantic notions as inborn.@@@@1@28@@danf@17-8-2009 10750300@unknown@formal@none@1@S@Thus, even novel concepts were proposed to have been dormant in some sense.@@@@1@13@@danf@17-8-2009 10750310@unknown@formal@none@1@S@This traditional view was also unable to address many issues such as [[metaphor]] or associative meanings, and [[semantic change]], where meanings within a linguistic community change over time, and [[qualia]] or subjective experience.@@@@1@33@@danf@17-8-2009 10750320@unknown@formal@none@1@S@Another issue not addressed by the nativist model was how perceptual cues are combined in thought, e.g. in [[mental rotation]].@@@@1@20@@danf@17-8-2009 10750330@unknown@formal@none@1@S@This traditional view of semantics, as an innate finite meaning inherent in a [[lexical unit]] that can be composed to generate meanings for larger chunks of discourse, is now being fiercely debated in the emerging domain of [[cognitive linguistics]] and also in the non-[[Jerry Fodor|Fodorian]] camp in [[Philosophy of Language]].@@@@1@50@@danf@17-8-2009 10750340@unknown@formal@none@1@S@The challenge is motivated by@@@@1@5@@danf@17-8-2009 10750350@unknown@formal@none@1@S@* factors internal to language, such as the problem of resolving [[indexical]] or [[anaphora]] (e.g. ''this x'', ''him'', ''last week'').@@@@1@20@@danf@17-8-2009 10750360@unknown@formal@none@1@S@In these situations "context" serves as the input, but the interpreted utterance also modifies the context, so it is also the output.@@@@1@22@@danf@17-8-2009 10750370@unknown@formal@none@1@S@Thus, the interpretation is necessarily dynamic and the meaning of sentences is viewed as context-change potentials instead of [[propositions]].@@@@1@19@@danf@17-8-2009 10750380@unknown@formal@none@1@S@* factors external to language, i.e. language is not a set of labels stuck on things, but "a toolbox, the importance of whose elements lie in the way they function rather than their attachments to things."@@@@1@36@@danf@17-8-2009 10750390@unknown@formal@none@1@S@This view reflects the position of the later [[Wittgenstein]] and his famous ''game'' example, and is related to the positions of [[Willard Van Orman Quine|Quine]], [[Donald Davidson (philosopher)|Davidson]], and others.@@@@1@30@@danf@17-8-2009 10750400@unknown@formal@none@1@S@A concrete example of the latter phenomenon is semantic [[underspecification]] — meanings are not complete without some elements of context.@@@@1@20@@danf@17-8-2009 10750410@unknown@formal@none@1@S@To take an example of a single word, "red", its meaning in a phrase such as ''red book'' is similar to many other usages, and can be viewed as compositional.@@@@1@30@@danf@17-8-2009 10750420@unknown@formal@none@1@S@However, the colours implied in phrases such as "red wine" (very dark), and "red hair" (coppery), or "red soil", or "red skin" are very different.@@@@1@25@@danf@17-8-2009 10750430@unknown@formal@none@1@S@Indeed, these colours by themselves would not be called "red" by native speakers.@@@@1@13@@danf@17-8-2009 10750440@unknown@formal@none@1@S@These instances are contrastive, so "red wine" is so called only in comparison with the other kind of wine (which also is not "white" for the same reasons).@@@@1@28@@danf@17-8-2009 10750450@unknown@formal@none@1@S@This view goes back to [[Ferdinand de Saussure|de Saussure]]:@@@@1@9@@danf@17-8-2009 10750460@unknown@formal@none@1@S@:Each of a set of synonyms like ''redouter'' ('to dread'), ''craindre'' ('to fear'), ''avoir peur'' ('to be afraid') has its particular value only because they stand in contrast with one another.@@@@1@31@@danf@17-8-2009 10750470@unknown@formal@none@1@S@No word has a value that can be identified independently of what else is in its vicinity.@@@@1@17@@danf@17-8-2009 10750480@unknown@formal@none@1@S@and may go back to earlier [[India]]n views on language, especially the [[Nyaya]] view of words as [[Semantic indicator|indicators]] and not carriers of meaning.@@@@1@24@@danf@17-8-2009 10750490@unknown@formal@none@1@S@An attempt to defend a system based on propositional meaning for semantic underspecification can be found in the [[Generative Lexicon]] model of [[James Pustejovsky]], who extends contextual operations (based on type shifting) into the lexicon.@@@@1@35@@danf@17-8-2009 10750500@unknown@formal@none@1@S@Thus meanings are generated on the fly based on finite context.@@@@1@11@@danf@17-8-2009 10750510@unknown@formal@none@1@S@===Prototype theory===@@@@1@2@@danf@17-8-2009 10750520@unknown@formal@none@1@S@Another set of concepts related to fuzziness in semantics is based on [[Prototype Theory|prototype]]s.@@@@1@14@@danf@17-8-2009 10750530@unknown@formal@none@1@S@The work of [[Eleanor Rosch]] and [[George Lakoff]] in the 1970s led to a view that natural categories are not characterizable in terms of necessary and sufficient conditions, but are graded (fuzzy at their boundaries) and inconsistent as to the status of their constituent members.@@@@1@45@@danf@17-8-2009 10750540@unknown@formal@none@1@S@Systems of categories are not objectively "out there" in the world but are rooted in people's experience.@@@@1@17@@danf@17-8-2009 10750550@unknown@formal@none@1@S@These categories evolve as [[learning theory (education)|learned]] concepts of the world — meaning is not an objective truth, but a subjective construct, learned from experience, and language arises out of the "grounding of our conceptual systems in shared [[embodied philosophy|embodiment]] and bodily experience".@@@@1@43@@danf@17-8-2009 10750560@unknown@formal@none@1@S@A corollary of this is that the conceptual categories (i.e. the lexicon) will not be identical for different cultures, or indeed, for every individual in the same culture.@@@@1@28@@danf@17-8-2009 10750570@unknown@formal@none@1@S@This leads to another debate (see the [[Whorf-Sapir hypothesis]] or [[Eskimo words for snow]]).@@@@1@14@@danf@17-8-2009 10750580@unknown@formal@none@1@S@==Computer science==@@@@1@2@@danf@17-8-2009 10750590@unknown@formal@none@1@S@In [[computer science]], where it is considered as an application of [[mathematical logic]], semantics reflects the meaning of programs or functions.@@@@1@21@@danf@17-8-2009 10750600@unknown@formal@none@1@S@In this regard, semantics permits programs to be separated into their syntactical part (grammatical structure) and their semantic part (meaning).@@@@1@20@@danf@17-8-2009 10750610@unknown@formal@none@1@S@For instance, the following statements use different syntaxes (languages), but result in the same semantic:@@@@1@15@@danf@17-8-2009 10750620@unknown@formal@none@1@S@* x += y; ([[C (programming language)|C]], [[Java (programming language)|Java]], etc.)@@@@1@11@@danf@17-8-2009 10750630@unknown@formal@none@1@S@* x := x + y; ([[Pascal (programming language)|Pascal]])@@@@1@9@@danf@17-8-2009 10750640@unknown@formal@none@1@S@* Let x = x + y; (early [[BASIC]])@@@@1@9@@danf@17-8-2009 10750650@unknown@formal@none@1@S@* x = x + y (most BASIC dialects, [[Fortran]])@@@@1@10@@danf@17-8-2009 10750660@unknown@formal@none@1@S@Generally these operations would all perform an arithmetical addition of 'y' to 'x' and store the result in a variable 'x'.@@@@1@21@@danf@17-8-2009 10750670@unknown@formal@none@1@S@Semantics for computer applications falls into three categories:@@@@1@8@@danf@17-8-2009 10750680@unknown@formal@none@1@S@* [[Operational semantics]]: The meaning of a construct is specified by the computation it induces when it is executed on a machine.@@@@1@22@@danf@17-8-2009 10750690@unknown@formal@none@1@S@In particular, it is of interest ''how'' the effect of a computation is produced.@@@@1@14@@danf@17-8-2009 10750700@unknown@formal@none@1@S@* [[Denotational semantics]]: Meanings are modelled by mathematical objects that represent the effect of executing the constructs.@@@@1@17@@danf@17-8-2009 10750710@unknown@formal@none@1@S@Thus ''only'' the effect is of interest, not how it is obtained.@@@@1@12@@danf@17-8-2009 10750720@unknown@formal@none@1@S@* [[Axiomatic semantics]]: Specific properties of the effect of executing the constructs as expressed as ''assertions''.@@@@1@16@@danf@17-8-2009 10750730@unknown@formal@none@1@S@Thus there may be aspects of the executions that are ignored.@@@@1@11@@danf@17-8-2009 10750740@unknown@formal@none@1@S@The '''[[Semantic Web]]''' refers to the extension of the [[World Wide Web]] through the embedding of additional semantic [[metadata]]; s.a.@@@@1@20@@danf@17-8-2009 10750750@unknown@formal@none@1@S@[[Web Ontology Language]] (OWL).@@@@1@4@@danf@17-8-2009 10750760@unknown@formal@none@1@S@==Psychology==@@@@1@1@@danf@17-8-2009 10750770@unknown@formal@none@1@S@In [[psychology]], ''[[semantic memory]]'' is memory for meaning, in other words, the aspect of memory that preserves only the ''gist'', the general significance, of remembered experience, while [[episodic memory]] is memory for the ephemeral details, the individual features, or the unique particulars of experience.@@@@1@44@@danf@17-8-2009 10750780@unknown@formal@none@1@S@Word meaning is measured by the company they keep; the relationships among words themselves in a [[semantic network]].@@@@1@18@@danf@17-8-2009 10750790@unknown@formal@none@1@S@In a network created by people analyzing their understanding of the word (such as [[Wordnet]]) the links and decomposition structures of the network are few in number and kind; and include "part of", "kind of", and similar links.@@@@1@38@@danf@17-8-2009 10750800@unknown@formal@none@1@S@In automated [[ontologies]] the links are computed vectors without explicit meaning.@@@@1@11@@danf@17-8-2009 10750810@unknown@formal@none@1@S@Various automated technologies are being developed to compute the meaning of words: [[latent semantic indexing]] and [[support vector machines]] as well as [[natural language processing]], [[neural networks]] and [[predicate calculus]] techniques.@@@@1@31@@danf@17-8-2009 10750820@unknown@formal@none@1@S@Semantics has been reported to drive the course of psychotherapeutic interventions.@@@@1@11@@danf@17-8-2009 10750830@unknown@formal@none@1@S@Language structure can determine the treatment approach to drug-abusing patients. .@@@@1@11@@danf@17-8-2009 10750840@unknown@formal@none@1@S@While working in Europe for the US Information Agency, American psychiatrist, Dr. A. James Giannini reported semantic differences in medical approaches to addiction treatment..@@@@1@24@@danf@17-8-2009 10750850@unknown@formal@none@1@S@English speaking countries used the term "drug dependence" to describe a rather passive pathology in their patients.@@@@1@17@@danf@17-8-2009 10750860@unknown@formal@none@1@S@As a result the physician's role was more active.@@@@1@9@@danf@17-8-2009 10750870@unknown@formal@none@1@S@Southern European countries such as Italy and Yugoslavia utilized the concept of "tossicomania" (i.e. toxic mania) to describe a more acive rather than passive role of the addict.@@@@1@28@@danf@17-8-2009 10750880@unknown@formal@none@1@S@As a result the treating physician's role shifted to that of a more passive guide than that of an active interventionist. .@@@@1@22@@danf@17-8-2009 10760010@unknown@formal@none@1@S@
Sentence (linguistics)
@@@@1@2@@danf@17-8-2009 10760020@unknown@formal@none@1@S@In [[linguistics]], a '''sentence''' is a grammatical unit of one or more words, bearing minimal syntactic relation to the words that precede or follow it, often preceded and followed in speech by pauses, having one of a small number of characteristic intonation patterns, and typically expressing an independent statement, question, request, command, etc.@@@@1@53@@danf@17-8-2009 10760030@unknown@formal@none@1@S@Sentences are generally characterized in most languages by the presence of a [[finite verb]], e.g. "[[The quick brown fox jumps over the lazy dog]]".@@@@1@24@@danf@17-8-2009 10760050@unknown@formal@none@1@S@==Components of a sentence==@@@@1@4@@danf@17-8-2009 10760060@unknown@formal@none@1@S@A simple ''complete sentence'' consists of a ''[[subject (grammar)|subject]]'' and a ''[[predicate (grammar)|predicate]]''.@@@@1@13@@danf@17-8-2009 10760070@unknown@formal@none@1@S@The subject is typically a [[noun phrase]], though other kinds of phrases (such as [[gerund]] phrases) work as well, and some languages allow subjects to be omitted.@@@@1@27@@danf@17-8-2009 10760080@unknown@formal@none@1@S@The predicate is a finite [[verb phrase]]: it's a finite verb together with zero or more [[object (grammar)|objects]], zero or more [[complement (linguistics)|complements]], and zero or more [[adverbial]]s.@@@@1@28@@danf@17-8-2009 10760090@unknown@formal@none@1@S@See also [[copula]] for the consequences of this verb on the theory of sentence structure.@@@@1@15@@danf@17-8-2009 10760100@unknown@formal@none@1@S@===Clauses===@@@@1@1@@danf@17-8-2009 10760110@unknown@formal@none@1@S@A [[clause]] consists of a subject and a verb.@@@@1@9@@danf@17-8-2009 10760120@unknown@formal@none@1@S@There are two types of clauses: independent and subordinate (dependent).@@@@1@10@@danf@17-8-2009 10760130@unknown@formal@none@1@S@An independent clause consists of a subject verb and also demonstrates a complete thought: for example, "I am sad."@@@@1@19@@danf@17-8-2009 10760140@unknown@formal@none@1@S@A subordinate clause consists of a subject and a verb, but demonstrates an incomplete thought: for example, "Because I had to move."@@@@1@22@@danf@17-8-2009 10760150@unknown@formal@none@1@S@==Classification==@@@@1@1@@danf@17-8-2009 10760160@unknown@formal@none@1@S@===By structure===@@@@1@2@@danf@17-8-2009 10760170@unknown@formal@none@1@S@One traditional scheme for classifying [[English language|English]] sentences is by the number and types of [[finite verb|finite]] [[clause]]s:@@@@1@18@@danf@17-8-2009 10760180@unknown@formal@none@1@S@* A ''[[simple sentence]]'' consists of a single [[independent clause]] with no [[dependent clause]]s.@@@@1@14@@danf@17-8-2009 10760190@unknown@formal@none@1@S@* A ''[[compound sentence (linguistics)|compound sentence]]'' consists of multiple independent clauses with no dependent clauses.@@@@1@15@@danf@17-8-2009 10760200@unknown@formal@none@1@S@These clauses are joined together using [[grammatical conjunction|conjunctions]], [[punctuation]], or both.@@@@1@11@@danf@17-8-2009 10760210@unknown@formal@none@1@S@* A ''[[complex sentence]]'' consists of one or more independent clauses with at least one dependent clause.@@@@1@17@@danf@17-8-2009 10760220@unknown@formal@none@1@S@* A ''[[complex-compound sentence]]'' (or ''compound-complex sentence'') consists of multiple independent clauses, at least one of which has at least one dependent clause.@@@@1@23@@danf@17-8-2009 10760230@unknown@formal@none@1@S@===By purpose===@@@@1@2@@danf@17-8-2009 10760240@unknown@formal@none@1@S@Sentences can also be classified based on their purpose:@@@@1@9@@danf@17-8-2009 10760250@unknown@formal@none@1@S@*A ''declarative sentence'' or ''declaration'', the most common type, commonly makes a statement: ''I am going home.''@@@@1@17@@danf@17-8-2009 10760260@unknown@formal@none@1@S@*A ''negative sentence'' or ''[[negation (linguistics)|negation]]'' denies that a statement is true: ''I am not going home.''@@@@1@17@@danf@17-8-2009 10760270@unknown@formal@none@1@S@*An ''interrogative sentence'' or ''[[question]]'' is commonly used to request information — ''When are you going to work?'' — but sometimes not; ''see'' [[rhetorical question]].@@@@1@25@@danf@17-8-2009 10760280@unknown@formal@none@1@S@*An ''exclamatory sentence'' or ''[[exclamation]]'' is generally a more emphatic form of statement: ''What a wonderful day this is!''@@@@1@19@@danf@17-8-2009 10760290@unknown@formal@none@1@S@===Major and minor sentences===@@@@1@4@@danf@17-8-2009 10760300@unknown@formal@none@1@S@A major sentence is a ''regular'' sentence; it has a [[subject (grammar)|subject]] and a [[predicate (grammar)|predicate]].@@@@1@16@@danf@17-8-2009 10760310@unknown@formal@none@1@S@For example: ''I have a ball.''@@@@1@6@@danf@17-8-2009 10760320@unknown@formal@none@1@S@In this sentence one can change the persons: ''We have a ball.''@@@@1@12@@danf@17-8-2009 10760330@unknown@formal@none@1@S@However, a minor sentence is an irregular type of sentence.@@@@1@10@@danf@17-8-2009 10760340@unknown@formal@none@1@S@It does not contain a finite verb.@@@@1@7@@danf@17-8-2009 10760350@unknown@formal@none@1@S@For example, "Mary!"@@@@1@3@@danf@17-8-2009 10760360@unknown@formal@none@1@S@"Yes."@@@@1@1@@danf@17-8-2009 10760370@unknown@formal@none@1@S@"Coffee." etc.@@@@1@2@@danf@17-8-2009 10760380@unknown@formal@none@1@S@Other examples of minor sentences are headings (e.g. the heading of this entry), stereotyped expressions (''Hello!''), emotional expressions (''Wow!''), proverbs, etc.@@@@1@21@@danf@17-8-2009 10760390@unknown@formal@none@1@S@This can also include sentences which do not contain verbs (e.g. ''The more, the merrier.'') in order to intensify the meaning around the nouns (normally found in poetry and catchphrases) by Judee N..@@@@1@33@@danf@17-8-2009 10770010@unknown@formal@none@1@S@
Computer software
@@@@1@2@@danf@17-8-2009 10770020@unknown@formal@none@1@S@'''Computer software,''' or just '''software''' is a general term used to describe a collection of [[computer program]]s, [[procedures]] and documentation that perform some tasks on a computer system.@@@@1@28@@danf@17-8-2009 10770030@unknown@formal@none@1@S@The term includes [[application software]] such as [[word processor]]s which perform productive tasks for users, [[system software]] such as [[operating system]]s, which interface with [[hardware]] to provide the necessary services for application software, and [[middleware]] which controls and co-ordinates [[Distributed computing|distributed systems]].@@@@1@42@@danf@17-8-2009 10770040@unknown@formal@none@1@S@"Software" is sometimes used in a broader context to mean anything which is not hardware but which is ''used'' with hardware, such as film, tapes and records.@@@@1@27@@danf@17-8-2009 10770050@unknown@formal@none@1@S@==Relationship to computer hardware==@@@@1@4@@danf@17-8-2009 10770060@unknown@formal@none@1@S@[[Computer]] software is so called to distinguish it from [[computer hardware]], which encompasses the physical interconnections and devices required to store and execute (or run) the software.@@@@1@27@@danf@17-8-2009 10770070@unknown@formal@none@1@S@At the lowest level, software consists of a [[machine language]] specific to an individual processor.@@@@1@15@@danf@17-8-2009 10770080@unknown@formal@none@1@S@A machine language consists of groups of binary values signifying processor instructions which change the state of the computer from its preceding state.@@@@1@23@@danf@17-8-2009 10770090@unknown@formal@none@1@S@Software is an ordered sequence of instructions for changing the state of the computer hardware in a particular sequence.@@@@1@19@@danf@17-8-2009 10770100@unknown@formal@none@1@S@It is usually written in [[high-level programming language]]s that are easier and more efficient for humans to use (closer to [[natural language]]) than machine language.@@@@1@25@@danf@17-8-2009 10770110@unknown@formal@none@1@S@High-level languages are [[compiler|compiled]] or [[interpreter (computing)|interpreted]] into machine language object code.@@@@1@12@@danf@17-8-2009 10770120@unknown@formal@none@1@S@Software may also be written in an [[assembly language]], essentially, a mnemonic representation of a machine language using a natural language alphabet.@@@@1@22@@danf@17-8-2009 10770130@unknown@formal@none@1@S@Assembly language must be assembled into object code via an [[assembly language#Assembler|assembler]].@@@@1@12@@danf@17-8-2009 10770140@unknown@formal@none@1@S@The term "software" was first used in this sense by [[John W. Tukey]] in [[1958]].@@@@1@15@@danf@17-8-2009 10770150@unknown@formal@none@1@S@In [[computer science]] and [[software engineering]], '''computer software''' is all computer programs.@@@@1@12@@danf@17-8-2009 10770160@unknown@formal@none@1@S@The theory that is the basis for most modern software was first proposed by [[Alan Turing]] in his [[1935]] essay ''Computable numbers with an application to the Entscheidungsproblem''.@@@@1@28@@danf@17-8-2009 10770170@unknown@formal@none@1@S@==Types==@@@@1@1@@danf@17-8-2009 10770180@unknown@formal@none@1@S@Practical [[computer system]]s divide [[software system]]s into three major classes: [[system software]], [[programming software]] and [[application software]], although the distinction is arbitrary, and often blurred.@@@@1@25@@danf@17-8-2009 10770190@unknown@formal@none@1@S@*'''[[System software]]''' helps run the [[computer hardware]] and [[computer system]].@@@@1@10@@danf@17-8-2009 10770200@unknown@formal@none@1@S@It includes [[operating system]]s, [[device driver]]s, diagnostic tools, [[Server (computing)|server]]s, [[windowing system]]s, [[software utility|utilities]] and more.@@@@1@16@@danf@17-8-2009 10770210@unknown@formal@none@1@S@The purpose of systems software is to insulate the applications programmer as much as possible from the details of the particular computer complex being used, especially memory and other hardware features, and such as accessory devices as communications, printers, readers, displays, keyboards, etc.@@@@1@43@@danf@17-8-2009 10770220@unknown@formal@none@1@S@*'''[[Programming software]]''' usually provides tools to assist a [[programmer]] in writing [[computer program]]s, and software using different [[programming language]]s in a more convenient way.@@@@1@24@@danf@17-8-2009 10770230@unknown@formal@none@1@S@The tools include [[text editors]], [[compilers]], [[interpreter (computing)|interpreters]], [[linkers]], [[debuggers]], and so on.@@@@1@13@@danf@17-8-2009 10770240@unknown@formal@none@1@S@An [[Integrated development environment]] (IDE) merges those tools into a software bundle, and a programmer may not need to type multiple [[command]]s for compiling, interpreting, debugging, tracing, and etc., because the IDE usually has an advanced ''[[graphical user interface]],'' or GUI.@@@@1@41@@danf@17-8-2009 10770250@unknown@formal@none@1@S@*'''[[Application software]]''' allows end users to accomplish one or more specific (non-computer related) [[task]]s.@@@@1@14@@danf@17-8-2009 10770260@unknown@formal@none@1@S@Typical applications include [[Industry|industrial]] [[automation]], [[business software]], [[educational software]], [[medical software]], [[database]]s, and [[computer games]].@@@@1@15@@danf@17-8-2009 10770270@unknown@formal@none@1@S@Businesses are probably the biggest users of application software, but almost every field of human activity now uses some form of application software@@@@1@23@@danf@17-8-2009 10770280@unknown@formal@none@1@S@==Program and library==@@@@1@3@@danf@17-8-2009 10770290@unknown@formal@none@1@S@A [[Computer program|program]] may not be sufficiently complete for execution by a [[computer]].@@@@1@13@@danf@17-8-2009 10770300@unknown@formal@none@1@S@In particular, it may require additional software from a [[software library]] in order to be complete.@@@@1@16@@danf@17-8-2009 10770310@unknown@formal@none@1@S@Such a library may include software components used by [[stand-alone]] programs, but which cannot work on their own.@@@@1@18@@danf@17-8-2009 10770320@unknown@formal@none@1@S@Thus, programs may include standard routines that are common to many programs, extracted from these libraries.@@@@1@16@@danf@17-8-2009 10770330@unknown@formal@none@1@S@Libraries may also ''include'' 'stand-alone' programs which are activated by some [[event-driven programming|computer event]] and/or perform some function (e.g., of computer 'housekeeping') but do not return data to their calling program.@@@@1@31@@danf@17-8-2009 10770340@unknown@formal@none@1@S@Libraries may be [[Execution (computers)|called]] by one to many other programs; programs may call zero to many other programs.@@@@1@19@@danf@17-8-2009 10770350@unknown@formal@none@1@S@==Three layers==@@@@1@2@@danf@17-8-2009 10770360@unknown@formal@none@1@S@Users often see things differently than programmers.@@@@1@7@@danf@17-8-2009 10770370@unknown@formal@none@1@S@People who use modern general purpose computers (as opposed to [[embedded system]]s, [[analog computer]]s, [[supercomputer]]s, etc.) usually see three layers of software performing a variety of tasks: platform, application, and user software.@@@@1@32@@danf@17-8-2009 10770380@unknown@formal@none@1@S@;Platform software:@@@@1@2@@danf@17-8-2009 10770390@unknown@formal@none@1@S@[[Platform (computing)|Platform]] includes the [[firmware]], [[device driver]]s, an [[operating system]], and typically a [[graphical user interface]] which, in total, allow a user to interact with the computer and its [[peripheral]]s (associated equipment).@@@@1@32@@danf@17-8-2009 10770400@unknown@formal@none@1@S@Platform software often comes bundled with the computer.@@@@1@8@@danf@17-8-2009 10770410@unknown@formal@none@1@S@On a [[Personal computer|PC]] you will usually have the ability to change the platform software.@@@@1@15@@danf@17-8-2009 10770420@unknown@formal@none@1@S@;Application software:@@@@1@2@@danf@17-8-2009 10770430@unknown@formal@none@1@S@[[Application software]] or Applications are what most people think of when they think of software.@@@@1@15@@danf@17-8-2009 10770440@unknown@formal@none@1@S@Typical examples include office suites and video games.@@@@1@8@@danf@17-8-2009 10770450@unknown@formal@none@1@S@Application software is often purchased separately from computer hardware.@@@@1@9@@danf@17-8-2009 10770460@unknown@formal@none@1@S@Sometimes applications are bundled with the computer, but that does not change the fact that they run as independent applications.@@@@1@20@@danf@17-8-2009 10770470@unknown@formal@none@1@S@Applications are almost always independent programs from the operating system, though they are often tailored for specific platforms.@@@@1@18@@danf@17-8-2009 10770480@unknown@formal@none@1@S@Most users think of compilers, databases, and other "system software" as applications.@@@@1@12@@danf@17-8-2009 10770490@unknown@formal@none@1@S@;User-written software:@@@@1@2@@danf@17-8-2009 10770500@unknown@formal@none@1@S@[[End-user development]] tailors systems to meet users' specific needs.@@@@1@9@@danf@17-8-2009 10770510@unknown@formal@none@1@S@User software include spreadsheet templates, word processor macros, scientific simulations, and scripts for graphics and animations.@@@@1@16@@danf@17-8-2009 10770520@unknown@formal@none@1@S@Even email filters are a kind of user software.@@@@1@9@@danf@17-8-2009 10770530@unknown@formal@none@1@S@Users create this software themselves and often overlook how important it is.@@@@1@12@@danf@17-8-2009 10770535@unknown@formal@none@1@S@Depending on how competently the user-written software has been integrated into purchased application packages, many users may not be aware of the distinction between the purchased packages, and what has been added by fellow co-workers.@@@@1@35@@danf@17-8-2009 10770540@unknown@formal@none@1@S@==Creation==@@@@1@1@@danf@17-8-2009 10770550@unknown@formal@none@1@S@==Operation==@@@@1@1@@danf@17-8-2009 10770560@unknown@formal@none@1@S@Computer software has to be "loaded" into the [[computer storage|computer's storage]] (such as a ''[[hard drive]]'', ''memory'', or ''[[RAM]]'').@@@@1@19@@danf@17-8-2009 10770570@unknown@formal@none@1@S@Once the software has loaded, the computer is able to ''execute'' the software.@@@@1@13@@danf@17-8-2009 10770580@unknown@formal@none@1@S@This involves passing [[instruction (computer science)|instructions]] from the application software, through the system software, to the [[hardware]] which ultimately receives the instruction as [[machine language|machine code]].@@@@1@26@@danf@17-8-2009 10770590@unknown@formal@none@1@S@Each instruction causes the computer to carry out an operation -- moving [[data (computing)|data]], carrying out a [[computation]], or altering the [[control flow]] of instructions.@@@@1@25@@danf@17-8-2009 10770600@unknown@formal@none@1@S@Data movement is typically from one place in memory to another.@@@@1@11@@danf@17-8-2009 10770610@unknown@formal@none@1@S@Sometimes it involves moving data between memory and registers which enable high-speed data access in the CPU.@@@@1@17@@danf@17-8-2009 10770620@unknown@formal@none@1@S@Moving data, especially large amounts of it, can be costly.@@@@1@10@@danf@17-8-2009 10770630@unknown@formal@none@1@S@So, this is sometimes avoided by using "pointers" to data instead.@@@@1@11@@danf@17-8-2009 10770640@unknown@formal@none@1@S@Computations include simple operations such as incrementing the value of a variable data element.@@@@1@14@@danf@17-8-2009 10770650@unknown@formal@none@1@S@More complex computations may involve many operations and data elements together.@@@@1@11@@danf@17-8-2009 10770660@unknown@formal@none@1@S@Instructions may be performed sequentially, conditionally, or iteratively.@@@@1@8@@danf@17-8-2009 10770670@unknown@formal@none@1@S@Sequential instructions are those operations that are performed one after another.@@@@1@11@@danf@17-8-2009 10770680@unknown@formal@none@1@S@Conditional instructions are performed such that different sets of instructions execute depending on the value(s) of some data.@@@@1@18@@danf@17-8-2009 10770690@unknown@formal@none@1@S@In some languages this is known as an "if" statement.@@@@1@10@@danf@17-8-2009 10770700@unknown@formal@none@1@S@Iterative instructions are performed repetitively and may depend on some data value.@@@@1@12@@danf@17-8-2009 10770710@unknown@formal@none@1@S@This is sometimes called a "loop."@@@@1@6@@danf@17-8-2009 10770720@unknown@formal@none@1@S@Often, one instruction may "call" another set of instructions that are defined in some other program or [[module (programming)|module]].@@@@1@19@@danf@17-8-2009 10770730@unknown@formal@none@1@S@When more than one computer processor is used, instructions may be executed simultaneously.@@@@1@13@@danf@17-8-2009 10770740@unknown@formal@none@1@S@A simple example of the way software operates is what happens when a user selects an entry such as "Copy" from a menu.@@@@1@23@@danf@17-8-2009 10770750@unknown@formal@none@1@S@In this case, a conditional instruction is executed to copy text from data in a 'document' area residing in memory, perhaps to an intermediate storage area known as a 'clipboard' data area.@@@@1@32@@danf@17-8-2009 10770760@unknown@formal@none@1@S@If a different menu entry such as "Paste" is chosen, the software may execute the instructions to copy the text from the clipboard data area to a specific location in the same or another document in memory.@@@@1@37@@danf@17-8-2009 10770770@unknown@formal@none@1@S@Depending on the application, even the example above could become complicated.@@@@1@11@@danf@17-8-2009 10770780@unknown@formal@none@1@S@The field of [[software engineering]] endeavors to manage the complexity of how software operates.@@@@1@14@@danf@17-8-2009 10770790@unknown@formal@none@1@S@This is especially true for software that operates in the context of a large or powerful [[computer system]].@@@@1@18@@danf@17-8-2009 10770800@unknown@formal@none@1@S@Currently, almost the only limitations on the use of computer software in applications is the ingenuity of the designer/programmer.@@@@1@19@@danf@17-8-2009 10770810@unknown@formal@none@1@S@Consequently, large areas of activities (such as playing grand master level chess) formerly assumed to be incapable of software simulation are now routinely programmed.@@@@1@24@@danf@17-8-2009 10770820@unknown@formal@none@1@S@The only area that has so far proved reasonably secure from software simulation is the realm of human art— especially, pleasing music and literature.@@@@1@24@@danf@17-8-2009 10770830@unknown@formal@none@1@S@Kinds of software by operation: [[computer program]] as [[executable]], [[source code]] or [[script (computer programming)|script]], [[computer configuration|configuration]].@@@@1@17@@danf@17-8-2009 10770840@unknown@formal@none@1@S@==Quality and reliability==@@@@1@3@@danf@17-8-2009 10770850@unknown@formal@none@1@S@[[Software reliability]] considers the errors, faults, and failures related to the design, implementation and operation of software.@@@@1@17@@danf@17-8-2009 10770860@unknown@formal@none@1@S@'''See''' [[Computer security audit|Software auditing]], [[Software quality]], [[Software testing]], and [[Software reliability]].@@@@1@12@@danf@17-8-2009 10770870@unknown@formal@none@1@S@==License==@@@@1@1@@danf@17-8-2009 10770880@unknown@formal@none@1@S@[[Software license]] gives the user the right to use the software in the licensed environment, some software comes with the license when purchased off the shelf, or an OEM license when bundled with hardware.@@@@1@34@@danf@17-8-2009 10770890@unknown@formal@none@1@S@Other software comes with a [[free software licence]], granting the recipient the rights to modify and redistribute the software.@@@@1@19@@danf@17-8-2009 10770900@unknown@formal@none@1@S@Software can also be in the form of [[freeware]] or [[shareware]].@@@@1@11@@danf@17-8-2009 10770910@unknown@formal@none@1@S@See also [[License Management]].@@@@1@4@@danf@17-8-2009 10770920@unknown@formal@none@1@S@==Patents==@@@@1@1@@danf@17-8-2009 10770930@unknown@formal@none@1@S@The issue of [[software patent]]s is controversial.@@@@1@7@@danf@17-8-2009 10770940@unknown@formal@none@1@S@Some believe that they hinder [[software development]], while others argue that software patents provide an important incentive to spur software innovation.@@@@1@21@@danf@17-8-2009 10770950@unknown@formal@none@1@S@See [[software patent debate]].@@@@1@4@@danf@17-8-2009 10770960@unknown@formal@none@1@S@==Ethics and rights for software users==@@@@1@6@@danf@17-8-2009 10770970@unknown@formal@none@1@S@Being a new part of society, the idea of what rights users of software should have is not very developed.@@@@1@20@@danf@17-8-2009 10770980@unknown@formal@none@1@S@Some, such as the [[free software community]], believe that software users should be free to modify and redistribute the software they use.@@@@1@22@@danf@17-8-2009 10770990@unknown@formal@none@1@S@They argue that these rights are necessary so that each individual can control their computer, and so that everyone can cooperate, if they choose, to work together as a community and control the direction that software progresses in.@@@@1@38@@danf@17-8-2009 10770995@unknown@formal@none@1@S@Others believe that software authors should have the power to say what rights the user will get.@@@@1@17@@danf@17-8-2009 10771000@unknown@formal@none@1@S@==Software companies and non-profit organizations==@@@@1@5@@danf@17-8-2009 10771010@unknown@formal@none@1@S@Examples of non-profit software organizations : [[Free Software Foundation]], [[GNU Project]], [[Mozilla Foundation]]@@@@1@13@@danf@17-8-2009 10771020@unknown@formal@none@1@S@Examples of large software companies are: [[Microsoft]], [[IBM]], [[Oracle_Corporation|Oracle]], [[SAP AG|SAP]] and [[HP]].@@@@1@13@@danf@17-8-2009