This study investigates changing family relationships during adolescence using a dialectical view of the family. Fifty-one families responded to an assessment battery that measured affective relations between parents and their adolescent children. Measures included the Transition into Adolescence Survey; the Interactive Behavior Questionnaire; the Parental Control Questionnaire; the Decision-Making Questionnaire; and the Issues Checklist. Families were classified into prepubertal, transpubertal, or postpubertal groups according to their modal response on Tanner's (1962) physical status criteria. A stepwise discriminant analysis was performed to identify measures that maximize between groups differences. Based on that analysis, a correct classification rate of 70 percent was achieved. A multiple discriminant analysis was then performed to determine if these groups could be classified based upon their resposes to the entire assessment battery. Based on this analysis, a correct classification rate of 86 percent was achieved. The two significant discriminant functions that emerged indicate that changes in family relationships are related to the transformation of mother-adolescent and father-adolescent relations. These results are discussed with respect to the dimensionalization of change in the affective nature of family relations during adolescence. (Author/RH)