Test–retest reliability and practice effects on a shortened version of the Category Switch Task–a pilot study

Test–retest reliability and practice effects have not been assessed for the Category Switch Task (CST), a task-switching paradigm readily available to researchers. Forty-eight participants completed a shortened CST twice. Test–retest intervals were either same day, one day, or one week. Test–retest reliability was assessed via Pearson’s correlation and intraclass correlation coefficient. Practice Effects were assessed using paired-samples t-tests, and the effect of interval was examined through a series of ANCOVAs. Single task, switch cost and mixing cost response time test–retest reliability was comparable to other task-switching paradigms, while reliability for switch and mixing cost accuracy was poor. Test–retest Practice Effects were present for single task response time and accuracy, and mixing cost response time. Of these, Practice Effects varied as a function of interval only for single task accuracy, where an interval of one week resulted in a smaller improvement compared to one day. Results and implications for use are discussed.