The Impact of Item-Writing Flaws on Difficulty and Discrimination in Item Response Theory

Abstract

High-quality test items are essential for educational assessments, particularly within Item Response Theory (IRT). Traditional validation methods rely on resource-intensive pilot testing to estimate item difficulty and discrimination. More recently, Item-Writing Flaw (IWF) rubrics emerged as a domain-general approach for evaluating test items based on textual features. This method offers a scalable, pre-deployment evaluation without requiring student data, but its predictive validity concerning empirical IRT parameters is underexplored. To address this gap, we conducted a study involving 7,126 multiple-choice questions across various STEM subjects (physical science, mathematics, and life/earth sciences). Using an automated approach, we annotated each question with a 19-criteria IWF rubric and studied relationships to data-driven IRT parameters. Our analysis revealed statistically significant links between the number of IWFs and IRT difficulty and discrimination parameters, particularly in life/earth and physical science domains. We further observed how specific IWF criteria can impact item quality more and less severely (e.g., negative wording vs. implausible distractors) and how they might make a question more or less challenging. Overall, our findings establish automated IWF analysis as a valuable supplement to traditional validation, providing an efficient method for initial item screening, particularly for flagging low-difficulty MCQs. Our findings show the need for further research on domain-general evaluation rubrics and algorithms that understand domain-specific content for robust item validation.