Stability of the Wisconsin Card Sorting Test and the Determination of Reliability of Change in Scores

It has been argued that the Wisconsin Card Sorting Test (WCST) is not suitable for repeated administrations because people benefit from prior exposure to the test. This study examined the stability of nine variables from the WCST in two groups, examined on two occasions approximately nine months apart. In a non-brain-injured group, correlations on eight WCST variables were stable, with coefficients at rI = 0.67 and above, yet the magnitude of change between test occasions was small (maximum 0.33 standard deviations). These results suggest that the WCST is suitable for repeated administrations. The data also provided the basis for clinical decision-making in individuals, in terms of determining the reliability of change in scores from one test administration to another. Application of this procedure to individuals from a traumatically brain-injured group was demonstrated.