Free reference · 596 entries
The words, before the course.
Short, plain definitions of the terms that turn up in statistics and data science — what they mean, and how they relate to each other. Nothing to sign in for.
12 of 596 entries under V
- Validation SampleThe validation sample is the subset of the data available to a data mining routine used as the validation set.
- Validation SetA validation set is a portion of a data set used in data mining to assess the performance of prediction or classification models that have been fit on a separate portion of the same data set (the training set).
- ValidityValidity characterises the extent to which a measurement procedure is capable of measuring what it is supposed to measure.
- Variable-Selection ProceduresIn regression analysis, variable-selection procedures are aimed at selecting a reduced set of the independent variables – the ones providing the best fit to the model.
- Variable-Selection Procedures (Graphical)In regression analysis, variable-selection procedures are aimed at selecting a reduced set of the independent variables – the ones providing the best fit to the model.
- Variables (in design of experiments)Many statistical methods rest on a statistical model which states a relationship Y = f(X1,..,XN) between a dependent variable (Y) and independent variable(s) X1,…,XN.
- VarianceVariance is a measure of dispersion. It is the average squared distance between the mean and each item in the population or in the sample.
- Variance/Mean RatioVariance/mean ratio (VMR) is used to characterize the distribution of events or objects in time or space.
- Variance/Mean Ratio TestThe variance/mean ratio (VMR) test is a statistical test used to test the null hypothesis that the variance/mean ratio is 1.0.
- VariateThe term “variate” is often used as synonym for “variable”. Some definitions require that variate values be numeric.
- Vector Autoregressive ModelsVector autoregressive models describe statistical properties of vector time series. Vector autoregressive models generalize the models used in ordinary autoregression.
- Vector time seriesVector time series are a natural generalization of ordinary (scalar) time series. Vector time series are measurements of a vector variable taken at regular intervals over time.
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