Statistical approaches to achieving sufficiently high test score reliabilities for research purposes.

The author provides statistical approaches to aid investigators in assuring that sufficiently high test score reliabilities are achieved for specific research purposes. The statistical approaches use tests of statistical significance between the obtained reliability and lowest population reliability that an investigator will tolerate. The statistical approaches work for coefficient alpha and related coefficients and for alternate-forms, split-half (2-part alpha), and retest reliabilities. The author shows that, in some instances, a formula can help to estimate the sample size necessary for the statistical test.