Order of item difficulty on the WAIS-R picture arrangement subtest: data from a traumatically brain-injured sample.

Although the items within the WAIS-R subtests are presumed to be in ascending order of difficulty, several studies have indicated that the Picture Arrangement subtest items are out of order for clinical groups. The present study retrospectively examined item difficulty and discrimination in the test data of 74 individuals who had been referred for neuropsychological assessment following a traumatic brain injury. While results were not statistically significant, qualitative analysis of partial credit scoring for four of the items indicated some inconsistencies in the scoring rationale. Caution is recommended in the use and interpretation of the Picture Arrangement tests scores in the assessment of individuals with traumatic brain injury.