Find peer-reviewed, published research using the Inquisit Digit Span
Lumiley, F. H., and Calhoon, S. W.(1934). Memory Span for Words Presented Auditorially. Applied Psychology, 18, 773-784.
Blankenship, A.B. (1938). Memory span: A review of the literature. Psychological Bulletin, 35, 1-25.
Daneman, M., & Carpenter, P. A. (1980). Individual differences in working memory and reading. Journal of Verbal Learning and Verbal Behavior, 19, 450-466.
Drewnowski, A., Murdock, B. B. (1980). The role of auditory features in memory span for words. Journal of Experimental Psychology: Human Learning and Memory, 6, 319 – 332.
Conway, A. R. A., Kane, M. J., Bunting, M. F., Hambrick, D. Z., Wilhelm, O., & Engle, R. W. (2005). Working memory span tasks: A methodological review and user’s guide. Psychonomic Bulletin & Review, 12, 769-786.