Advancing HRD measurement: a comprehensive guide to IRT and GRM in an international context

This is the authors' abstract. We don't add key points for this paper.

This method paper provides basic information about Item Response Theory (IRT). Item Response Theory is not a theory in the traditional sense. It is a psychometric theory that mathematically relates a respondent’s latent trait or ability score with the probability of him or her choosing a certain answer on an instrument’s item. IRT is a fairly new method of measurement construction relative to the Classical Test Theory (CTT). In this paper we briefly discuss CTT and its limitations. Then, we introduce the foundational concepts of IRT. Our focus in this article is the Graded Response Model (GRM). GRM is one of the IRT models that are used for polytomous items such as Likert scale. Using simulated data, we demonstrate the use of GRM on Likert scale data. In addition, our paper emphasises the importance of measurement invariance for International Human Resource Development. We explain and demonstrate Measurement Invariance analysis using IRT. We close our article by discussing the benefits of using IRT and conducting measurement invariance in international Human Resource Development.