The Effect of Word-Finding Difficulties on Intellectual Assessment

Abstract

Professionals believe that students' language and learning challenges frequently complicate interpretation of their intelligence test scores. One specific language difficulty that has the potential to affect students' cognitive test performance is difficulty in word finding. This investigation examined the influence of students' word-finding difficulties on their test performance on the WISC-R. Eighty-one fourth- and fifth-grade students with learning disabilities with WISC-R subscale scores on file were administered the Test of Word Finding (TWF). Classification of the LD sample by word-finding skills formed the basis for group comparisons. Initial analysis of variance using composite IQs as the unit of analysis indicated that students with word-finding difficulties earned significantly lower mean WISCR Verbal IQs than did students without word-finding difficulties, whereas mean differences in the Performance Scale IQs did not differ significantly. An initial multivariate analysis of variance (MANOVA), treating the 10 WISC-R subtests as the dependent variable set, was also statistically significant (p< .05). Univariate F tests and eta-squared values were used as post hoc indicators of variable importance to differentiate between students with and without word-finding difficulties in the LD population. Significant differences in word-finding group means emerged on the Information, Similarities ("large” effect range), and Comprehension subtests ("medium” effect range). Neither Vocabulary, Arithmetic, nor Performance subscale mean differences were statistically significant. A “retrieval deficit hypothesis” is presented as an explanation for the Verbal subtest score differences, suggesting that students' performance on these subtests appears influenced by students' word-finding difficulties. A Word-Finding adapted-assessment approach is presented as a practical solution to this assessment dilemma.