PSYCHOMETRIC PROPERTIES OF RUSSEL SHORT-FORM OF THE BOOKLET CATEGORY TEST

Russell's short form of the Booklet Category Test was administered to 26 diagnosed schizophrenic patients and 14 normal individuals along with a test of premorbid intelligence. IQ correlated significantly (inversely) with errors and in particular with Subtests 3, 4, and 6. Age related directly to errors, especially for Subtests 3, 4, and 5. The mean Cronbach coefficient alpha was .71, indicating moderate item homogeneity across subtests. In sum, the shortened form appears to be an efficient and effective measure of concept formation among schizophrenic individuals.