xvariables

XVariables is a term used in statistics and data analysis to denote the collection of independent or predictor variables used in a model. The plural XVariables stands for the matrix X of predictor values, where rows are observations and columns are variables.

In traditional linear or generalized linear modeling, XVariables are contrasted with the dependent variable Y. The coefficients for XVariables express the estimated effect of each predictor on the outcome given the other predictors; the quality of the model depends on the choice and coding of XVariables.

In practice, XVariables may be subject to feature engineering, encoding of categorical variables, scaling, and selection. Multicollinearity among XVariables can affect estimates and interpretability. Regularization methods can mitigate this.

In software and data pipelines, XVariables is sometimes used as a namespace or concept describing the set of inputs to a modeling function, or a data frame containing the predictor columns. Some libraries provide utilities to automatically assemble, standardize, or transform XVariables before fitting a model.

See also: independent variable, predictor variable, features, design matrix, multicollinearity, feature engineering.