AbstractA group of 80 mentally retarded youngsters, aged 6 to 16, was tested on the WISC‐R, primarily to assess the continuity of measurement between the old and new WISCs. The WISC‐R IQs correlated .65 to .82 with Stanford‐Binet IQ for a subsample of 45 children, resembling the coefficients between the 1949 WISC and the Binet for retarded groups. In addition, the WISC‐R test profiles for the 80 children corresponded closely to the WISC test profiles for many retarded samples. Thus, there was evidence to support the continuity of the WISC‐R with its predecessor for retarded po