Use of item response theory in marketing research

Abstract

There are three purposes of this paper. The first is to present a brief introduction to item response theory in conjunction with marketing research. The second is to present a review of the current uses of item response theory in representative marketing research journals. The third is to present an example that illustrate and contrasts classical test theory and item response theory approaches to item and scale analysis. Several item response theory relevant papers were recently published in various marketing research journals. Because models under item response theory, from simple to complex, were used without any systematic introduction in marketing research, this paper briefly presents the main concepts in item response theory. A content analysis was done for the second purpose with 30 item response theory relevant articles in marketing research journals. Articles were sorted based on the taxonomy of item response theory models. Many articles reviewed relied on some type of unidimensional dichotomous item response theory models. Articles published recently within the past 10 years used more complicated item response theory models, both mathematically and statistically, than other previously published articles in marketing research journals. Lastly, data from a scale with three Likert-type items of four response categories were analysed using a traditional approach based on item statistics and coefficient alpha as well as using an item response theory approach by employing the graded response model. Main concepts of item response theory were explicated with figures.