aanalyze -> Regression ->Linear ->IV: put first the pretest in , method: ENTER, click on NEXT, than put in the intervention variable -STATISTICS: estimates, model fit, R²change, descriptives, collinearity diagnostics, Residuals: Durbin-Watson -SAVE: unstadardized Residuals -PLOT: Y:ZResid X:ZPred, select Histogramm and p-p plot