WAIS-R SUBTEST PATTERN CLUSTERS IN CLOSED-HEAD-INJURED AND HEALTHY SAMPLES

Cluster analysis was performed on the WAIS-R subtest scores of a close d-head-injured (CHI) sample (n = 233) in an attempt to replicate and e xtend the findings of Crosson, Greene, Roth, Farr, and Adams (1990). T he same analysis was also run with a healthy sample (n = 326) recruite d to match the general adult population in terms of demographic variab les; a subsample matched to the CHI sample was also formed (n = 117). Eleven clusters were extracted from the CHI sample, five of which cont ained 10 or more members. There was a low degree of correspondence bet ween these latter clusters and the six subtest patterns clusters repor ted by Crosson et al. The importance of Verbal/Performance discrepanci es in the formation of clusters in CHI was examined by comparing Verba l/Performance composites against arbitrary composites in CHI and healt hy samples. In the CHI sample both sets of composites yielded signific ant effects but a larger effect size was obtained for the Verbal/Perfo rmance composites. However, the same pattern of results was observed i n the healthy samples. Finally, a combined cluster analysis (N = 559) revealed that, although there was a significant difference in the numb er of CHI and healthy participants in each cluster, there was a high d egree of overlap in cluster membership.