Nonparametric item response theory for investigating dimensionality of marketing scales: A SERVQUAL application

Assessing scale dimensionality is an important issue in the marketing literature. In an exploratory context, principal axis factoring and principal components analysis receive emphasis, while other fields apply suitable alternatives. This article introduces a promising procedure known as Mokken scale analysis. Using an empirical data set, we demonstrate how Mokken scale analysis complements principal axis factoring and principal components analysis for gaining understanding of the dimensionality of the items in the SERVQUAL instrument.