While score comparability across test forms typically relies on common (or randomly equivalent) examinees or items, innovations in item formats, test delivery, and efforts to extend the range of score interpretation may require a special data collection before examinees or items can be used in this way--or may be incompatible with common examinee…

This paper summarizes some of the basic concepts in test equating. Various types of equating methods, as well as data collection designs, are outlined, with attempts to provide insight into preferred methods and techniques. Test equating describes a group of methods that enable test constructors and users to compare scores from two different forms…

In this paper a quadratic curve equating method for different test forms under a random-group data-collection design is proposed. Procedures for implementing this method and related issues are described and discussed. The quadratic-curve method was evaluated with real test data (from two 30-item subtests for a professional licensure examination…

Combinations of five methods of equating test forms and two methods of selecting samples of students for equating were compared for accuracy. The two sampling methods were representative sampling from the population and matching samples on the anchor test score. The equating methods were: (1) the Tucker method; (2) the Levine method; (3) the…