The Woodcock-Johnson Tests (WJ III) is a valid and reliable assessment tool of both cognitive abilities and achievement among children and adults. It is based on the most current theoretical model of intelligence, Cattell-Horn-Carroll (CHC) theory. The broad CHC abilities measured on one or more of the WJ Tests are: Long-Term Retrieval (Glr), Auditory Processing (Ga), Fluid Reasoning (Gf), Processing Speed (Gs), Short-Term Memory (Gsm), Visual-Spatial Thinking (Gv), Comprehension-Knowledge (Gc), Reading-Writing (Grw), and Quantitative Knowledge (Gq). The WJ III proves to be a valuable diagnostic tool to be used to identify exceptional children including high incidence disabilities like head injury, Attention Deficit and Hyperactivity Disorder ADHD; low incidence disabilities such as visual impairment and autism; and gifted students including those with a learning disability. Higher education students have benefit from WJ III tests as well.