Analysis of the Psychological Well-Being Scale for Adults using the graded response model

The Psychological Well-Being Scale for Adults (BIEPS-A) was proposed as a multidimensional measure of psychological well-being. The present study hypothesized that the BIEPS-A is an essentially unidimensional measure and, therefore, can be analysed with unidimensional item response theory models. We examined data from 1016 Peruvian undergraduates (Mage = 20.56, 50% women) and found support for our unidimensionality hypothesis. Thus, the graded response model was applied to the BIEPS-A items. All of them performed acceptably only at low levels of the construct, while they performed poorly at average and higher levels of psychological well-being. The implications of these findings are discussed and suggestions for future developments are also offered.