The development of two new rating scales, a classroom observation schedule and a comparable student self-report questionnaire, is described. Both instruments are designed to measure group self-concept, defined as a social structure exhibiting interactions which indicate values, attitudes, and beliefs that determine the self-perception of a group, wherein individuals mirror the composite group perceptions demonstrated through group behavior. The student self-report questionnaires were combined for all members of a class in order to obtain an average score for each item to represent the class score. The classroom observation schedules were completed by five pairs of trained observers in each of seven groups--three fourth grade classes, three fifth grade classes, and one seventh grade group that included three classes working together. The instruments were designed to record descriptions of behaviors in four categories: peer interactions, teacher-pupil interactions, pupil-environment interactions, and physical self-presentation. Factor analysis of the student self-report data revealed five oblique factors. Estimates were made of scale reliabilities and of content validities. (Author/CTM)