The file “ancova exercise.sav” includes simulated data for the ANCOVA example presented in the chapter (see also the Excel or plain text versions of this file). This was a pretest–posttest two-group design in which 60 students registered for a course in research methodology were assigned, at random, to a traditional version of the class or an Internet version of the class. All students attended an orientation session in which they were given a pretest of their research knowledge. The posttest scores are students’

grades for the class. Analyze the results of the experiment using multiple regression analysis. Test for the presence of an interaction between the pretest and the treatment

(type of class). Conduct any needed follow-up. Conduct an ANCOVA and compare the results of this analysis with those of the multiple regression.