The reliability and stability of the Turner and Engle working memory

Abstract

The present study explored the psychometric properties of Turner and Engle's (1989) operation span task, a widely used measure of working memory capacity. We administered the task three times to 33 college students, using equivalent test materials. The interval between the first and second administrations was 3 weeks, with 6-7 weeks between the second and third administrations. Alpha coefficients were all .75 or more. Recall accuracy decreased as operation set size increased. Raw test-retest correlations ranged from .67 to .81, the corrected reliability was .88, and stability scores ranged from .76 to .92. Performance improved from the first to the second test. Relative to reported reliabilities of other tasks used to assess individual differences in working memory capacity, the operation span task appears to have several statistical advantages.