factorsvariables
Factor variables, or categorical variables, take on a limited number of categories that identify groups rather than measure magnitude. They differ from numeric variables and are common in statistics and data science. Factor variables can be nominal, with no inherent order (for example, color: red, blue, green), or ordinal, with a meaningful sequence (such as education level: high school, bachelor’s, master’s, PhD). Some analyses treat ordered factors specially to reflect the order.
In data processing, a factor is described by its levels or categories. Analyses typically use indicator or
Software treats factors differently from numeric data. In R, a factor has levels and an order; in
Careful choice of reference level, level order, and handling of missing values affects interpretation and model