This study investigated the effects of short term supplemental parent and classroom programs on the self-concept, sociometric status, social involvement, and heterogeneity of friendship and associations of day care children 3.3 to 5 year of age. The treatment conditions compared: (1) a regular day care program (control); (2) a day care program with supplemental classroom activities designed to enhance specific social interaction skills; (3) a day care program with a supplemental parent program focusing on increasing positive parent-child and parent-teacher interaction; and (4) a day care program with both supplemental classroom and parent programs. Data were collected before and after the 12-week intervention period, from approximately 200 black and Anglo children in eight large day care centers, using the following instruments: Brown IDS Self-Concept Referents Test; Play Situation-Picture Board Sociometric; Classroom Socio-Observations; and the Observation and Socialization Behavior instrument (revised), a videotaped observational rating procedure. Significant differences across treatment conditions were evidenced on a number of variables. The appendices include supplemental information on the instruments used, sample lessons from classroom and parent programs, and descriptions of the centers involved. (ED)