Constructing personality scales under the assumptions of an ideal point response process: toward increasing the flexibility of personality measures

The main aim of this article is to explicate why a transition to ideal point methods of scale construction is needed to advance the field of personality assessment. The study empirically demonstrated the substantive benefits of ideal point methodology as compared with the dominance framework underlying traditional methods of scale construction. Specifically, using a large, heterogeneous pool of order items, the authors constructed scales using traditional classical test theory, dominance item response theory (IRT), and ideal point IRT methods. The merits of each method were examined in terms of item pool utilization, model-data fit, measurement precision, and construct and criterion-related validity. Results show that adoption of the ideal point approach provided a more flexible platform for creating future personality measures, and this transition did not adversely affect the validity of personality test scores.