Investigating the Function of Content and Argumentation Items in a Science Test: A Multidimensional Approach

The latest national science framework has formally stated the need for developing assessments that test both students' content knowledge and scientific practices. In response to this call, a science assessment that consists of (a) content items that measure students' understanding of a grade eight physics topic and (b) argumentation items that measure students' argumentation competency has been developed. This paper investigated the function of these content and argumentation items with a multidimensional measurement framework from two perspectives. First, we performed a dimensionality analysis to investigate whether the relationship between the content and argumentation items conformed to test deign. Second, we conducted a differential item functioning analysis in the multidimensional framework to examine if any content or argumentation item unfairly favored students with an advanced level of English literacy. Methods and findings of this study could inform future research on the validation of assessments measuring higher-order and complex abilities.