The previous edition WJ III was praised for covering "a wide variety of cognitive skills".
[3] The Cattell–Horn–Carroll theory factors that this test examines are based on 9 broad stratum abilities, although the test is able to produce 20 scores[4] only seven of these broad abilities are more commonly measured: comprehension-knowledge (Gc), fluid reasoning (Gf), short-term memory (Gsm), processing speed (Gs), auditory processing (Ga), visual-spatial ability (Gv), and long-term storage and retrieval (Glr).
Comprehension-knowledge (Gc) is the ability to use previous experience, knowledge, and skills, which are valued by one’s culture, to communicate or reason in unique situations.
Processing speed (Gs) is the ability to execute simple and repetitive cognitive tasks rapidly and effortlessly.
[6] The Woodcock-Johnson III and IV are suitable for assessment of giftedness,[7][8] and for referrals for special education services.