Reliability methods: A note on the frequency of use of various types

This study examined the frequency of use of various types of reliability co efficients fora systematically drawn sample of 696 tests appearing in the A PA-published Directory of Unpublished Experimental Mental Measures. Almost all articles included some type of reliability report for at least one test administration. Coefficient alpha was the overwhelming favorite among type s of coefficients. Several measures treated almost universally in psycholog ical-testing textbooks were rarely or never used. Problems encountered in t he study included ambiguous designations of types of coefficients, reportin g reliability based on a study other than the one cited, inadequate informa tion about subscales, and simply incorrect recording of the information giv en in an original source.