EVALUATING THE EFFECTIVENESS OF TWO-STAGE TESTING ON ENGLISH AND FRENCH VERSIONS OF A SCIENCE ACHIEVEMENT TEST

The current study evaluated the effectiveness of two-stage testing on English and French versions of a science achievement test administered to a national sample in Canada in 1996 and 1999. The tests were administered and scored with the implicit assumption that the two language forms were equivalent. Analysis of the first-stage test revealed that 3 out of 12 items displayed differential item functioning (DIF) in both administrations. However, substantive reviews suggested that translation errors were not the cause of DIF. Analysis of the second-stage test revealed that the test was not comparable between ability groups but was comparable for English and French examinees within each ability group in both administrations. This study illustrates how test developers can monitor their adaptation and administration process when alternative testing procedures are used with multiple language groups. The results are also relevant to cross-cultural researchers who compare examinees from different ethnic and cultural backgrounds.