My son's RIAS scores were significantly higher than his WISC-IV scores, largely due to his WISC-IV scores being depressed by significant visual-motor disabilities and Asperger's syndrome. The RIAS did a much better job of capturing the level of "intellectual horsepower" and reasoning ability that we saw at home, due to the lack of motor output required, the clearer format of the visual items, and the lack of social comprehension questions, while the WISC did a better job of showing his areas of weakness and identifying what areas needed further assessment.