Readability level of standardized test items and student performance: The forgotten validity variable

Abstract Test validity issues considered by test developers and school districts rarely include individual item readability levels. In this study, items from a major standardized test were examined for individual item readability level and item difficulty. The Homan‐Hewitt Readability Formula was applied to items across three grade levels. Results of correlations of readability level and item difficulty at all three levels support the belief that the higher the item readability, the more students miss that item. A possible conclusion is that students miss items due to reading problems, not because of a lack of content knowledge. These data appear to support measuring individual item readability on standardized tests.