The dimensionality of a placement test from several analytical perspectives

Abstract

In order to find the most appropriate group for students enrolling in FSL classes at the postsecondary level, a placement test has been designed. The purpose of this test is to measure general proficiency in the language. Using IRT procedures, an adaptive version has been developed. The test consists of three parts: comprehension of a short paragraph, selection of the appropriate statement in a situation and a 'fill-the-gap' part. Different approaches to assess the unidimensionality are used: structural equation approach (LIS REL), factor-analysis approach (TESTFACT), nonparametric approach (Stout's procedure) and IRT-based approach (Bejar's procedure). These approaches are complementary. The subtests generally meet the unidi mensionality assumption for IRT although they measure more than one ability.