ABSTRACT
The tests described in this chapter deal with the analysis of experiments in which the scores of two independent groups of subjects are to be compared. As suggested in Chapter 1, this design is not particularly sensitive to the effects of the independent variable because subject differences tend to obscure the experimental effects. Nevertheless, much psychological research is based on the independent groups design. This is due partly to its simplicity-one merely divides the subjects into two groups on a random basis-and partly to the lack of any practicable alternative in certain situations, for example, when performance in one condition of an experiment destroys a subject’s usefulness in the other.
