An Item Response Theory for Personality and Attitude Scales: Item Analysis Using Restricted Factor Analysis

This paper describes the applicability of item re sponse theory to attitude scale development and pro vides an illustration derived from a study of the pro pensity toward jealousy in romantic relationships. The item analysis model used is identical to the factor analysis model, so factor analytic criteria are used to evaluate the scale. These criteria may be used to de cide whether the scale may be scored as a measure of a single variable and whether a simple sum or a weighted sum of the item responses serves as an opti mal test score. Estimates of the reliability of the scale based on the item response model are also described.