BRIEF REPORT Incomplete Psychometric Equivalence of Scores Obtained on the Manual and the Computer Version of the Wisconsin Card Sorting Test? Jean-Paul Steinmetz and Martin Brunner University of Luxembourg Even Loarer National Institute for Research on Labor and Vocational Guidance Claude Houssemand University of Luxembourg The Wisconsin Card Sorting Test (WCST) assesses executive and frontal lobe function and can be administered manually or by computer. Despite the widespread application of the 2 versions, the psychometric equivalence of their scores has rarely been evaluated and only a limited set of criteria has been considered. The present experimental study (N = 100 healthy adults) therefore examined the psychometric equivalence of 4 scores (i.e., Total Correct, Percentage of Errors, Perseverative Errors, and Failure-to-Maintain-Set) obtained on the 2 versions of the WCST in terms of 4 key criteria identified within the framework of classical test theory. The results showed considerable differences in variances, small to modest parallel-forms reliability coefficients, and small to modest temporal stability coefficients. Taken together, our results suggest that scores on the manual version and the computer version of the WCST show incomplete psychometric equivalence. Keywords: Wisconsin Card Sorting Test, computerized assessment, psychometric score equivalence The Wisconsin Card Sorting Test (WCST) is widely used for assessing executive and frontal lobe functions (Heaton, Chelune, Talley, Kay, & Curtiss, 1993). There are two commercially avail- able versions of the WCST: a manual version (Heaton et al., 1993) and a computer version (Heaton & PAR Staff, 2003). Crucially, (a) normative data and (b) interpretative guidelines are available for the manual version but not for the computer version. This raises the question of whether scores obtained on the two versions of the WCST can be considered to be psychometrically equivalent, meaning that a person’s cognitive functioning is judged in the same way, independently of the version applied. The purpose of the present experimental study was to rigorously investigate the score equivalence of the two versions of the WCST. The Wisconsin Card Sorting Test The basic idea of the WCST is that participants match response cards to key cards according to a nonspecified matching rule, which changes every time that 10 (out of a maximum of 128) response cards have been sorted correctly. The test yields a number of psychometric scores: First, the total number of correctly matched response cards (or Total Correct) is an indicator of overall performance. Second, Per- centage of Errors is an alternative indicator of overall performance. This score is computed by dividing the total number of incorrectly sorted response cards by the total number of response cards sorted and multiplying this value by 100 percent. Third, Perseverative Errors occur when a participant continues sorting response cards according to a matching rule after it has been changed. Perseverative Errors are highly relevant for clinical assessment because this type of error is considered to be an indicator of frontal lobe dysfunction (Heaton et al., 1993). Fourth, a Failure-to-Maintain-Set is scored when a participant gives five or more (but fewer than 10) consecutive correct responses and then makes an error (Heaton et al., 1993). This score thus indicates difficulties in applying a matching rule over an extended period of time and may also be indicative of neuropsychological deficits. Research Objectives Can we hypothesize a priori whether the scores obtained on the manual and the computer version of the WCST are psychometrically equivalent? Unfortunately, there is no substantive theory that would allow predictions to be made on how individual differences in, for example, computer anxiety, computer familiarity, or computer atti- Jean-Paul Steinmetz, Martin Brunner, and Claude Houssemand, Centre for Educational Measurement and Applied Cognitive Science, University of Luxembourg, Walferdange, Luxembourg; Even Loarer, National Insti- tute for Research on Labor and Vocational Guidance, Paris, France. Parts of this study have been presented at the XXIX International Congress of Psychology, Berlin, Germany, July 21–25, 2008, and at the 18th International Congress of Differential Psychology, Geneva, Switzer- land, August 23–26, 2008. We are grateful to Susannah Goss for editing the manuscript. We thank Evelyne Leiner and Nadine Ru ¨disser for their assistance in collecting the data. Correspondence concerning this article should be addressed to Jean-Paul Steinmetz, Centre for Educational Measurement and Applied Cognitive Science, University of Luxembourg, B.P. 2, Route de Diekirch, L-7202 Walferdange, Luxembourg. E-mail: jean-paul.steinmetz@uni.lu Psychological Assessment © 2010 American Psychological Association 2010, Vol. 22, No. 1, 199 –202 1040-3590/10/$12.00 DOI: 10.1037/a0017661 199 This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly.