Applying a Multidimensional Item Response Theory Approach in Validating the Dimensionality of the Positive Youth Development Scale

Positive youth development has gained a lot of attention recently since it acts as a protective factor for several risk behaviors and other important life outcomes in adolescents and young adults. The main objective of this study was to explore the factorial structure of the Positive Youth Development Scale (PYDS) using multidimensional item response theory (MIRT). Three different models were examined: a unidimensional model, a multidimensional model with six distinct dimensions, and a multidimensional bifactor model, where each item was restricted to load simultaneously on a global positive development factor as well as a domain-specific one. Results indicated that the bifactor model provided superior model fit compared to the competing models, including a testlet and purified models. The study concludes with the advantages of MIRT models in dimensionality assessment and provides some suggestions for the improvement of the PYDS' item characteristics.