RELIABILITY OF MEASUREMENT IN PSYCHOLOGY - FROM SPEARMAN-BROWN TO MAXIMAL-RELIABILITY

The authors extend the usual approach to the assessment of test or rat er reliability to situations that have previously not been appropriate for the application of this standard (Spearman-Brown) approach. Speci fically, the authors (a) provide an accurate overall estimate of the r eliability of a test (or a panel of raters) comprising 2 or more diffe rent kinds of items (or raters), a quite common situation, and (b) pro vide a simple procedure for constructing the overall instrument when i t comprises 2 or more kinds of items, judges, or raters, each with its own costs and its own reliabilities.