ABSTRACT
Observed-score equating is the practice of using a transformation to map the observed scores on one test form to those on another, the latter typically being an older form with a well-established score scale intended to be maintained over time. Usually, number-correct scores are equated. If the target scale has a different range of possible values, it is common practice to still equate number-correct scores but follow up with a standard transformation to adjust for the differences in range between the equated scores and the target scale. A comprehensive review of the methods currently in use for observed-score equating is Kolen and Brennan (2014).
