Standardized testing is ubiquitous in educational assessment, but questions have been raised about the extent to which these test scores accurately reflect students' genuine knowledge and skills. To more rigorously investigate this issue, the current study employed a within-subject experimental design to examine item format effects on primary…

Background: A fundamental aim of standardized educational assessment is to achieve reliable discrimination between students differing in the knowledge, skills and abilities assessed. However, questions of the purity with which these tests index students' genuine abilities have arisen. Specifically, literacy and numeracy assessments may also engage…