Abstract
The effects of six classroom motivational treatments on 112 fifth and sixth grade students were measured using a difference score on a substitution task. Individual goal setting and competitive treatments, under reward and non-reward conditions, are analyzed by means of planned comparisons. Results indicate a significant interaction which suggests caution against an oversimplified interpretation of main effects. A S’s performance in a competitive treatment is shown to be dependent upon three factors: his initial ability relative to that of his classmates; the presence or absence of a reward; the homogeneous or heterogeneous nature of the group in competition. The evaluation of this significant 3-way interaction ( i. e., ability x reward x grouping) and comparisons of means suggest several tentative hypotheses and raise highly relevant questions regarding the use of classroom motivational techniques which are competitive in nature.