This paper reviews previous research into ability grouping and describes a study of the relationship of heterogeneous and homogeneous grouping plans on children's concepts of their interpersonal relationships with other students and their academic success. Most studies on the emotional impact of ability grouping indicated that being placed in the low group carries a certain social stigma, although findings in one study suggested that students of low ability levels have higher feelings of self-worth in homogeneous settings. Studies concerned with self-image and social relationships found that children were aware of grouping, even in heterogeneous classes, and that peer acceptance was greater in heterogeneous classes. Studies of attitude and self-concept of children in homogeneous grouping programs showed that these programs seemed to be most beneficial for children in the high status groups. In the study reported here 713 sixth grade students (356 homogeneously grouped, 357 heterogeneously grouped) from six elementary schools were administered a questionnaire devised to test the students' concepts of their interpersonal acceptance and academic success. Results indicated that homogeneously grouped children indicated more favorable adjustment to other children and schoolwork than heterogeneously grouped children, though there appeared to be as much, if not more, difference from class to class in each organizational plan than between the two large organizational plans. Some sex differences were found. Results were sufficiently varied to suggest that the entire grouping question should be studied in depth. (SB)