Regression analysis is a statistical process for
estimating the relationship between two or more variables. The
relationship is modeled as \(y \sim x\)
or \(y = f(x)\). Both model
descriptions indicate, that the variable \(y\) is a function of \(x\). Therefore, the variable \(y\) is denoted as the **response
variable** or **dependent variable**, whereas the
variable \(x\) is denoted as the
**predictor variable** or **independent
variable**.