When causal inferences are to be synthesized across multiple studies, efforts to establish the magnitude of a causal effect should be balanced by an effort to evaluate the generalizability of the effect. The evaluation of generalizability depends on two factors that are given little attention in current syntheses: construct validity and external…

Criticizes the research design in "The Small ICF/MR program: Dimensions of Quality and Cost" (Conroy), that found small Intermediate Care Facilities (ICF) for individuals with mental retardation are inferior to other community programs. Discusses the problem in selecting a control group on the basis of pretest matching. (CR)