An examination of problems inherent to class size concepts suggests possible arrangements, given limited resources, for providing optimal classroom environments. Among the problems in determining class size are ambiguous definitions, measurement problems, and contradictory research findings. Traditional definitions of class size ignore such practices as team teaching, volunteers, and ability grouping. Class size measurement problems arise when researchers use such inconsistent measures as pupil-teacher ratio, averages, teacher contact hours, or teacher load. These measures tend to obscure qualitative differences. Class size research falls into three general categories: academic achievement, process variables (teacher innovation, teaching styles, and teacher load), and financial dimensions. Academic achievement and process variables research produce contradictory results; research on costs, however, uniformly concurs that smaller classes cost more than larger ones. Given these problems, the study proposes building-level committees composed of the principal, several teachers, and parents who would focus on individual classes and contexts at the start of the academic year rather than on district-wide determinations of class size. Adjustment strategies available to such committees include modifying the distribution of instructional staff, altering instructional methods, altering the distribution of students, and eliminating negative factors such as the presence of disturbed children in large classes. (PB)