The classroom environment elicits social comparison behavior in which a student uses peers' performance as a gauge for his own self-assessment. Social comparison as it relates to ability is a four phase sequential process. In phase one, stimulation of social comparison is elicited through developmentally-determined cognitive capacities and motives and situationally-elicited motives. Social comparison information begins to influence 7 and 8 year old children and increases dramatically thereafter. Once social comparison interest is elicited, the individual moves into phase two, in which he behaves in ways designed to obtain comparison information. This acquisition behavior is twofold: the choice of comparison person(s), and the timing and mode of information acquisition. An individual's choice of a comparison person is based on the specific motive underlying comparison, the degree of satisfaction, and developmental/temporal needs. Once the comparative data are collected the individual enters phase three, in which he has a perception of his relative performance; i.e., superior, equal, inferior. The fourth and final phase of the process concerns the individual's reaction to perceived relative performance, both intrapersonally and interpersonally, on cognitive, affective, and behavioral levels. Intrapersonally, comparison information affects performance expectancies and attributes, self-concept, task performance, and self-reward. Peer performance attributes, attraction/popularity, competitiveness, aggression and classroom disruption are all possible interpersonal responses to social comparison. Implications for classroom design and educational goals are discussed. Extensive references complete the article. (BL)