Studies in education often report the differences between participants' and non-participants' test scores, course grades, retention, and other criteria. When participants' average performance is higher, it can be difficult to attribute the improvements to participation. Comparing participants and non-participants on other measures can strengthen…

This paper focuses on methodological issues in applying equipercentile equating methods to pairs of tests that do not meet the assumptions of equating. This situation is referred to as a concordance situation, as opposed to an equating situation, and the end result is a concordance table that gives "comparable" scores between the tests.…

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…

In a study of factors in the educational environment of the home, the school, and the peer group contributing to achievement and attitudes towards schooling at the upper primary and lower secondary school levels, an opportunity arose to examine the data available for configural and curvilinear relationships. Information was collected on 11…