Question: when is fsiq not interpretable?
Answer: Flanagan and Kaufman (2004), in Essentials of WISC-IV Assessment, deem the FSIQ “not interpretable” if Composite scores vary by 23 points (1.5 standard deviations) or more. The GAI utilizes only scores from the Verbal Comprehension and Perceptual Reasoning Composites, not Working Memory and Processing Speed.