Abstract

The Solomon four-group design (Solomon, 1949), where the priming effects of pre-intervention testing can be detected and accounted for, is often referred to in the literature as the epitome of experimental design in behavioural research. In this paper the extension of this design, to account for the effects of alternative sources being responsible for change in the experimental group, is discussed and demonstrated in an eight group design (N=1 723). The methodology suggested by Walton Braver and Braver (1988) was used to analyse the data. This method, as well as other approaches dealing with this complex design, is discussed.