What Is Actually Equated in “Test Equating”? A Didactic Note

The current literature on test equating generally defines it as the process necessary to obtain score comparability between different forms. definition is in contrast with Lord’s foundational paper which viewed required of measurement scale distinction notions and not trivial. difference explained by connecting these standard statistical concepts probability experiment, sample space, random variable. experiment underlying forms scores immediately gives us transformation a function mapping one form into other thus supports point view taken Lord. However, both appear rely idea an examinees implies notion scores. It shown how explicit choice two experiments just important for our theoretical understanding key but also has practical consequences.