An Australian validation of the kaufman brief intelligence test (k-bit) with adolescents with an intellectual disability

The Kaufman Brief Intelligence Test (K-BIT; Kaufman & Kaufman, 1990) provides a relatively quick assessment of intelligence. In this study we assessed the validity and reliability of the K-BIT with an Australian sample of adolescents with an intellectual disability (N = 107). To examine criterion validity, K-BIT scores were correlated with scores on the Coloured Progressive Matrices (CPM; Raven, 1956; r = .52), and the Wechsler Intelligence Test for Children - Revised (WISC-R; Wechsler, 1974; r =.73-75). Test-retest and split-half reliability of the K-BIT were also examined (r = .93 and .88 respectively). Finally, item analyses examined the difficulty and discriminability of individual items. The results revealed that the K-BIT composite score in general provides a valid and reliable estimate of intelligence for Australian adolescents with an intellectual disability, but that a higher standard error estimate should be used in interpreting scores of the overall composite and Matrices scores of the K-BIT for students with an intellectual disability within the age range of 13 to 17 years.