Classical Test Th, ory Reliability Estimates

It is incorrect to say "the test is reliable " because reliability is a function not only of the test itself, but of many factors. The present paper.e.xplains how different factors affect classical reliability estimates such as test-retest, interrater, internal consistency, and equivalent forms coefficients. Furthermore, the limits of classical test theory are demonstrated, and it is recommended that researchers, teachers, and psychologists instead utilize generalizability-theory estimates of reliability. Heuristic examples and detailed explanations make this discussion accessible even to those who are uninitiated in either classical test theory or generalizability theory. (Contains 2 figures, 10 tables, and 18 references.) (Author) * Reproductions supplied by EDRS are the best that can be made * * from the original document.