The Trends in International Mathematics and Science Study (TIMSS) was administered via computer, eTIMSS, for the first time in 2019. The purpose of this study was to investigate item block position and item format effect on eighth grade mathematics item easiness in low- and high-achieving countries of eTIMSS 2019. Item responses from Chile, Qatar,…

Research shows that test method can exert a significant impact on test takers' performance and thereby contaminate test scores. We argue that common test method can exert the same effect as common stimuli and violate the conditional independence assumption of item response theory models because, in general, subsets of items which have a shared…