Tau-U: A Quantitative Approach for Analysis of Single-Case Experimental Data in Aphasia Purpose Tau-U is a quantitative approach for analyzing single-case experimental design (SCED) data. It combines nonoverlap between phases with intervention phase trend and can correct for a baseline trend (Parker, Vannest, & Davis, 2011). We demonstrate the utility of Tau-U by comparing it with the standardized mean difference approach (Busk ... Research Note
Research Note  |   March 01, 2018
Tau-U: A Quantitative Approach for Analysis of Single-Case Experimental Data in Aphasia
 
Author Affiliations & Notes
  • Jaime B. Lee
    James Madison University, Harrisonburg, VA
  • Leora R. Cherney
    Shirley Ryan AbilityLab (formerly the Rehabilitation Institute of Chicago), IL
    Feinberg School of Medicine, Northwestern University, Chicago, IL
  • Disclosure: The authors have declared that no competing interests existed at the time of publication.
    Disclosure: The authors have declared that no competing interests existed at the time of publication. ×
  • Correspondence to Jaime B. Lee: lee2jb@jmu.edu
  • Editor: Margaret Blake
    Editor: Margaret Blake×
  • Associate Editor: Julie Wambaugh
    Associate Editor: Julie Wambaugh×
Article Information
Language Disorders / Aphasia / Special Issue: Select Papers From the 46th Clinical Aphasiology Conference / Research Notes
Research Note   |   March 01, 2018
Tau-U: A Quantitative Approach for Analysis of Single-Case Experimental Data in Aphasia
American Journal of Speech-Language Pathology, March 2018, Vol. 27, 495-503. doi:10.1044/2017_AJSLP-16-0197
History: Received October 30, 2016 , Revised March 16, 2017 , Accepted April 28, 2017
 
American Journal of Speech-Language Pathology, March 2018, Vol. 27, 495-503. doi:10.1044/2017_AJSLP-16-0197
History: Received October 30, 2016; Revised March 16, 2017; Accepted April 28, 2017

Purpose Tau-U is a quantitative approach for analyzing single-case experimental design (SCED) data. It combines nonoverlap between phases with intervention phase trend and can correct for a baseline trend (Parker, Vannest, & Davis, 2011). We demonstrate the utility of Tau-U by comparing it with the standardized mean difference approach (Busk & Serlin, 1992) that is widely reported within the aphasia SCED literature.

Method Repeated writing measures from 3 participants with chronic aphasia who received computer-based writing treatment are analyzed visually and quantitatively using both Tau-U and the standardized mean difference approach.

Results Visual analysis alone was insufficient for determining an effect between the intervention and writing improvement. The standardized mean difference yielded effect sizes ranging from 4.18 to 26.72 for trained items and 1.25 to 3.20 for untrained items. Tau-U yielded significant (p < .05) effect sizes for 2 of 3 participants for trained probes and 1 of 3 participants for untrained probes. A baseline trend correction was applied to data from 2 of 3 participants.

Conclusions Tau-U has the unique advantage of allowing for the correction of an undesirable baseline trend. Although further study is needed, Tau-U shows promise as a quantitative approach to augment visual analysis of SCED data in aphasia.

Acknowledgments
This study was funded by Grant 90IF0034 “Enhancing Written Communication in Persons with Aphasia: A Clinical Trial” by the U.S. Department of Health and Human Services, Administration on Community Living, National Institute on Disability, Independent Living, and Rehabilitation Research (PI: L. R. Cherney). Manuscript preparation was also supported under Grant 90RES5013 from the National Institute on Disability, Independent Living and Rehabilitation Research (PI: W. Rymer). Grantees undertaking projects under government sponsorship are encouraged to express freely their findings and conclusions. These contents, however, do not necessarily represent the policy of the U.S. Department of Health and Human Services, and one should not assume endorsement by the Federal Government.
Order a Subscription
Pay Per View
Entire American Journal of Speech-Language Pathology content & archive
24-hour access
This Article
24-hour access