Sample size requirements for reliability studies

Abstract
This paper provides exact power contours to guide the planning of reliability studies, where the parameter of interest is the coefficient of intraclass correlation p derived from a one‐way analysis of variance model. The contours display the required numbers of subjects k and number of repeated measurements n that provide 80 per cent power for testing Ho:ρ ⩽ ρo versus H1: ρ > ρo at the 5 per cent level of significance for selected values of po. We discuss the design considerations of these results.