Wechsler believed that non-verbal (performance-based) intelligence was equally important. He introduced the first Wechsler-Bellevue scale in 1939. Over decades, this evolved into the WAIS (1955), WAIS-R (1981), WAIS-III (1997), and the current (2008, with recent updates to norms). The WAIS IV was designed to be more user-friendly, clinically sensitive, and reflective of current neuroscience understanding of cognitive functioning.
Key Subtests: Block Design, Matrix Reasoning, Visual Puzzles. Test Wais Iv