Cronbach a의 성격 탐색

Research on the Nature of Cronbach a

By Cronbach, a is the average of all the possible split-half coefficients for a given test, and a is index or estimating coefficient of equivalence and homogeneity of items. This article investigated whether what he insisted is right or wrong, a is classified as a kind of reliability. Reliability means precise measurement. Then does a indicate degree of precise measurement? Investigation of these questions showed that a accords roughly with the average of all possible split-half coefficients but does not accord precisely, and a accords with homogeneity in some special cases but does not accord with homogeneity for the most part, a can have relation to precise measurement in practice by chance but a has no relation to it logically. These discordances result from the facts that a fundamentally and originally denote the degree of 'interaction' among items and subjects by a formula, and the a formula is inappropriate to denote the original meaning of reliability.