This study aims to compare the G and Phi coefficients as estimated by D studies for a measurement tool with the G and Phi coefficients obtained from real cases in which items of differing difficulty levels were added and also to determine the conditions under which the D studies estimated reliability coefficients closer to reality. The study group…

Findings from experimental studies have increasingly been used to inform policy in school settings. Thus far, the populations in many of these studies are typically defined in a cross-sectional context; namely, the populations are defined in the same academic year in which the study took place or the population is defined at a fixed time point.…