There are several teaching examples on how to develop statistical analyses using SPSS in the following books:

1. Landau, S. and Everitt, B. S.(2004). A Handbook of Statistical analyses using SPSS.

2.Howitt, D. and Cramer, D.(2008). Introduction to SPSS.

Regards,

Zuhair

Thank you, however I do not have access at this moment to these books.

Hi John,

as far as I see there are two common approaches to your problem:

1st: two-way repeated measures ANOVA

2nd: ANCOVA (analysis of covariance) with prescores as covariates

Read the implications of these two methods carefully.

You may also consult the following discussion which, however, refers to randomized trials:

Vickers AJ: Analysis of variance is easily misapplied in the analysis of randomized trials: A critique and discussion of alternative statistical approaches. Psychosom Med 2005;67:652-655;

Van Breukelen, G.J.P. (2006). ANCOVA versus change from baseline: More power in randomized studies, more bias in nonrandomized studies. Journal of Clinical Epidemiology, 59, 920–925

Cheers

Christian