Item Analysis

Item analysis is one of the essential steps in scale construction of personality assessment. It refers to the process of evaluating the quality of the items in an assessment so to identify the items to be retained, revised, or removed from the item pool. Item analysis focuses on item discrimination and item difficulty and involves qualitative and quantitative approaches. Classical test theory (CTT) has been the dominant framework in guiding item analysis, but item response theory (IRT) has been increasingly used in item analysis as well. This entry introduced the concepts of item discrimination and item difficulty and described both the CCT-based and IRT-based item analyses.