An artificial data set suggested by N. Mantel to illustrate stepwise regression methods.
A data frame with 5 observations on the following 4 variables.
Mantel, N. (1970). Why stepdown procedures in variable selection? Technometrics, 12, 621–625.
Weisberg, S. (2014). Applied Linear Regression, 4th edition. Hoboken NJ: Wiley.