Program Analysis of Service Systems (PASS 3) and Program Analysis of Service Systems' Implementation of Normalization Goals (PASSING) are used internationally to assess service quality in mental retardation and other fields. In two studies, we derived and cross-validated the factor structures of these program evaluation instruments. In Study 1, based on 626 PASS 3 evaluations, four factors provided a good fit to the cross-validation data. In Study 2, based on 633 PASSING evaluations, three factors furnished a good fit to the cross-validation data. Similarities between the two factor structures, parallels with the structural and functional service dimensions emphasized in ecological approaches to evaluation, and practical uses in program evaluation of subscales based on the factors were discussed.