Comparison of Single-Response Format and Forced-Choice Format Instruments Using Thurstonian Item Response Theory

One of the most cited methodological issues is with the response format, which is traditionally a single-response Likert response format. Therefore, our study aims to elucidate and illustrate an alternative response format and analytic technique, Thurstonian item response theory (IRT), for analyzing data from surveys using an alternate response format, the forced-choice format. Specifically, we strove to give a thorough introduction of Thurstonian IRT at a more elementary level than previous publications in order to widen the possible audience. This article presents analyses and comparison of two versions of a self-report scale, one version using a single-response format and the other using a forced-choice format. Drawing from lessons learned from our study and literature, we present a number of recommendations for conducting research using the forced-choice format and Thurstonian IRT, as well as suggested avenues for future research.