A researcher who studies a fixed group of people over a period of time is using the longitudinal method

DSM-5 diagnoses are grouped under 22 primary headings based on

a. presumed causes. b. biological factors. c. descriptive similarity. d. theoretical assumptions.

The smallest units of sound in a spoken language are known as __________

a) psycholinguistics. b) phonemes. c) heuristics. d) morphemes.