| Affiliation: | (1) Department of Educational Research Methodology, University of North Carolina at Greensboro, Greensboro, NC, USA;(2) Department of Psychology, University of North Carolina at Greensboro, P.O. Box 26170, Greensboro, NC 27402-6170, USA; |
| Abstract: | The Wisconsin Schizotypy Scales are widely used for assessing schizotypy in nonclinical and clinical samples. However, they were developed using classical test theory (CTT) and have not had their psychometric properties examined with more sophisticated measurement models. The present study employed item response theory (IRT) as well as traditional CTT to examine psychometric properties of four of the schizotypy scales on the item and scale level, using a large sample of undergraduate students (n = 6,137). In addition, we investigated differential item functioning (DIF) for sex and ethnicity. The analyses revealed many strengths of the four scales, but some items had low discrimination values and many items had high DIF. The results offer useful guidance for applied users and for future development of these scales. |
