Research strategies and research goals in the scientific study of the mentally subnormal.
D000367:Age Factors; D006127:Group Structure; D006801:Humans; D008607:Intellectual Disability; D007361:Intelligence Tests; D007858:Learning; D008570:Memory, Short-Term; D009042:Motivation; D012106:Research; D012494:Sampling Studies; D013223:Statistics as Topic