Brief assessment of schizotypy: Developing short forms of the Wisconsin Schizotypy Scales

The Wisconsin Schizotypy Scales—the Perceptual Aberration, Magical Ideation, Physical Anhedonia, and Revised Social Anhedonia Scales—have been used extensively since their development in the 1970s and 1980s. Based on psychometric analyses using item response theory, the present work presents 15-item short forms of each scale. In addition to being briefer, the short forms omit items with high differential item functioning. Based on data from a sample of young adults (n = 1144), the short forms have strong internal consistency, and they mirror effects found for the longer scales. They thus appear to be a good option for researchers interested in the brief assessment of schizotypic traits. The items are listed in an Appendix A

Rejoinder: The madness to our method: Some thoughts on divergent thinking

In this reply, the authors examine the madness to their method in light of the comments. Overall, the authors agree broadly with the comments; many of the issues will be settled only by future research. The authors disagree, though, that past research has proven past scoring methods—including the Torrance methods—to be satisfactory or satisfying. The authors conclude by offering their own criticisms of their method, of divergent thinking, and of the concept of domain-general creative abilities

Brief assessment of schizotypy: Developing short forms of the Wisconsin Schizotypy Scales

The Wisconsin Schizotypy Scales—the Perceptual Aberration, Magical Ideation, Physical Anhedonia, and Revised Social Anhedonia Scales—have been used extensively since their development in the 1970s and 1980s. Based on psychometric analyses using item response theory, the present work presents 15-item short forms of each scale. In addition to being briefer, the short forms omit items with high differential item functioning. Based on data from a sample of young adults (n = 1144), the short forms have strong internal consistency, and they mirror effects found for the longer scales. They thus appear to be a good option for researchers interested in the brief assessment of schizotypic traits. The items are listed in an Appendix A. Highlights Short forms (15 items each) of the Wisconsin Schizotypy Scales were developed. Based on IRT and DIF analyses, items with high discrimination but low DIF were selected. Internal consistency and intercorrelations were good and consistent with past work with the long scales. The brief scales had construct-consistent relations with measures of personality and mood disorder symptoms

Psychometric Properties of the Wisconsin Schizotypy Scales in an Undergraduate Sample: Classical Test Theory, Item Response Theory, and Differential Item Functioning

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. The items for the Wisconsin Schizotypy Scales are available from Thomas R. Kwapil

Assessment of Score Dependability of the Wisconsin Schizotypy Scales Using Generalizability Analysis

To investigate the reliability of the Wisconsin Schizotypy Scales, this study applied generalizability analysis with two college student samples who completed the scales at two time points. The results indicated that the Revised Social Anhedonia Scale had acceptable levels of score dependability, but that the score dependability for the other scales (the Physical Anhedonia Scale, the Perceptual Aberration Scale, and the Magical Ideation Scale) was below an acceptable level of .80. The patterns of variance components suggested that the scales’ items need improvement. Researchers can use the included tables to choose the number of items and occasions needed to get dependable score interpretations. This research was presented at the 2007 meeting of the Midwestern Psychological Association, Chicago, IL

Psychometric Properties of the Wisconsin Schizotypy Scales in an Undergraduate Sample: Classical Test Theory, Item Response Theory, and Differential Item Functioning

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. The items for the Wisconsin Schizotypy Scales are available from Thomas R. Kwapil