An Analysis of the Psychometric Properties of Dual Language Test Forms.

Many students in the United States who are required to take educational tests are not fully proficient in English. To address this problem, a state-mandated testing program created dual language English-Spanish versions of some of their tests. In this study, the psychometric properties of the English and dual language versions of a fourth-grade mathematics test were explored. Analyses of the consistency of test structure across the two forms were conducted using structural equation modeling and multidimensional scaling. Analyses of differential item functioning (DIF) were conducted using Poly-SIBTEST. The results suggest slight structural differences across the two versions of the test. Part of this difference was attributed to overall proficiency differences across the two studied groups, and part was attributed to DIF. The implications of the findings for future research in this area are discussed. (Contains 4 figures, 11 tables, and 28 references.) (Author/SLD)