Prediction of developmental attainments of institutionalized mentally retarded children.

Two regression equations using chronological age and either IQ or the Fisher and Zeaman K score were developed to predict Developmental Record ratings of institutionalized mentally retarded children over a 2-year interval (N = 200), a 4-year interval (N = 165), and an 8-year interval (N = 95). Although the correlations between predicted and obtained scores for both equations were quite high even over an 8-year interval, analysis of mean differences revealed that the equation using IQ yielded more accurate predictions. If future studies support the use of such equations with other subjects in other settings, they should be useful in estimating later developmental attainments of mentally retarded children.