If you want QQPlot and histogram of the residuals, you can get those plots directly from PROC GLM. For example, study the following code:   ods graphics on; proc glm data=sashelp.cars plots=DiagnosticsPanel; class Origin Type ; model Length=Origin Type /solution; run;   I don't understand your statement "all my response variables are the same with the same mean and standard deviation."  If the Staplelength variable is continuous, then your code should produce the plots that you expect.  If not, I suggest you look at the data. For example, plot a histogram of Staplelength.     ... View more