Theoretical and Practical Foundations of Mokken Scale Analysis in Psychology

Abstract Item Response Theory represents one of the major advances in the field of developing valid and reliable measures in psychology. Among the main models used in this perspective are the Rasch model and the logistic models. These parametric models, however, are not suitable for all applications in psychology, since a substantial number of databases in psychology do not satisfy the assumptions of these models: unidimensionality; latent monotonicity; local independence; and, for some models, non-intersecting functions. Given this framework, the objective of this study was to present the theoretical and practical foundations of Mokken Scale Analysis (MSA). We present some historical issues involving the development of MSA, in addition to the main characteristics and assumptions of the two models used in this perspective. After exemplifying a MSA application, limitations and final considerations are presented, supporting the decision-making process for researchers who come to use MSA.