Sequential reliability tests

Abstract

Sequential tests for a stepped-up reliability estimator and coefficient alpha are developed. In a series of monte carlo experiments, the efficiency of the tests relative to each other and to fixed-sample tests is established, as well as the robustness of the alpha test. Both tests proved to be efficient, and the alpha test proved to be reasonably robust to deviations from normality and deviations from equal item error variances. On average, 47% of the sample size can be saved if a sequential test is applied instead of a fixed-sample test. Index terms: monte carlo simulation, reliability hypothesis tests, sampling theory for reliability estimators, sequential probability ratio test.