Using Single-Case Designs in Practical Settings: Is Within-Subject Replication Always Necessary?


Behavior analysts have widely adopted and embraced within-subject replication through the use of reversal and multielement designs. However, the withdrawal of treatment, which is central to these designs, may not be desirable, feasible, or even ethical in practical settings. To examine this issue, we extracted 501 ABAB graphs from theses and dissertations to examine to what extent we would have reached correct or incorrect conclusions if we had based our analysis on the initial AB component only. In our first experiment, we examined the proportion of datasets for which the results of the first AB component matched the results of the subsequent phase reversals. In our second experiment, we calculated three effect size estimates for the same datasets to examine whether these measures could predict the relevance of conducting a within-subject replication. Our analyses indicated that the initial effects were successfully replicated at least once in approximately 85% of the cases and that effect size may predict the probability of within-subject replication. Overall, our results support the rather controversial proposition that it may be possible to set threshold values of effect size above which conducting a replication could be considered unnecessary. That said, more research is needed to confirm and examine the generalizability of these results prior to recommending changes in practice.

This is a preview of subscription content, log in to check access.

Fig. 1


  1. Christ, T. J. (2007). Experimental control and threats to internal validity of concurrent and nonconcurrent multiple baseline designs. Psychology in the Schools, 44, 451–459.

    Article  Google Scholar 

  2. Cohen, J. (1992). A power primer. Psychological Bulletin, 112, 155–159.

    Article  PubMed  Google Scholar 

  3. Ferron, J. M., & Levin, J. R. (2014). Single-case permutation and randomization statistical tests: present status, promising new developments. In T. R. Kratochwill & J. R. Levin (Eds.), Single-case intervention research: methodological and statistical advances (pp. 153–183). Washington, DC: American Psychological Association.

    Google Scholar 

  4. Fisher, W. W., Kelley, M. E., & Lomas, J. E. (2003). Visual aids and structured criteria for improving visual inspection and interpretation of single-case designs. Journal of Applied Behavior Analysis, 36, 387–406.

    Article  PubMed  PubMed Central  Google Scholar 

  5. Horner, R. H., Carr, E. G., Halle, J., McGee, G., Odom, S., & Wolery, M. (2005). The use of single-subject research to identify evidence-based practice in special education. Exceptional Children, 71, 165–179.

    Article  Google Scholar 

  6. Johnston, J. M., Carr, J. E., & Mellichamp, F. H. (2017). A history of the professional credentialing of applied behavior analysts. The Behavior Analyst. Advanced online publication, 40, 523–538.

    Article  Google Scholar 

  7. Kazdin, A. E. (2011). Single-case research designs (2nd ed.). New York: Oxford University Press.

    Google Scholar 

  8. Kratochwill, T. R., Hitchcock, J., Horner, R. H., Levin, J. R., Odom, S. L., Rindskopf, D. M., &Shadish, W. R. (2010). Single-case designs technical documentation. Retrieved from

  9. Krueger, T. K., Rapp, J. T., Ott, L. M., Lood, E. A., & Novotny, M. A. (2013). Detecting false positives in A-B designs: potential implications for practitioners. Behavior Modification, 37, 615–630.

    Article  PubMed  Google Scholar 

  10. Lanovaz, M. J., Huxley, S. C., & Dufour, M.-M. (2017). Using the dual-criteria methods to supplement visual inspection: an analysis of nonsimulated data. Journal of Applied Behavior Analysis, 50, 662–667.

    Article  PubMed  Google Scholar 

  11. Levin, J. R., Ferron, J. M., & Kratochwill, T. R. (2012). Nonparametric statistical tests for single-case systematic and randomized ABAB… AB and alternating treatment intervention designs: new developments, new directions. Journal of School Psychology, 50, 599–624.

    Article  PubMed  Google Scholar 

  12. Ma, H. H. (2006). An alternative method for quantitative synthesis of single-subject researches: percentage of data points exceeding the median. Behavior Modification, 30, 598–617.

    Article  PubMed  Google Scholar 

  13. Marquis, J. G., Horner, R. H., Carr, E. G., Turnbull, A. P., Thompson, M., Behrens, G. A., et al. (2000). A meta-analysis of positive behavior support. In R. Gersten, E. P. Schiller, & S. Vaughn (Eds.), Contemporary special education research: syntheses of knowledge base on critical instructional issues (pp. 137–178). Mahwah: Erlbaum.

    Google Scholar 

  14. Moeyaert, M., Maggin, D., & Verkuilen, J. (2016). Reliability, validity, and usability of data extraction programs for single-case research designs. Behavior Modification, 40, 874–900.

    Article  PubMed  Google Scholar 

  15. Ninci, J., Vannest, K. J., Willson, V., & Zhang, N. (2015). Interrater agreement between visual analysts of single-case data: a meta-analysis. Behavior Modification, 39, 510–541.

    Article  PubMed  Google Scholar 

  16. Novotny, M. A., Sharp, K. J., Rapp, J. T., Jelinski, J. D., Lood, E. A., & Steffes, A. K. (2014). False positives with visual analysis for nonconcurrent multiple baseline designs and ABAB designs: preliminary findings. Research in Autism Spectrum Disorders, 8, 933–943.

    Article  Google Scholar 

  17. Ombudsman Ontatrio. (2016). Nowhere to turn: investigation into the Ministry of Community and Social Services’ response to situations of crisis involving adults with developmental disabilities Retrieved from

  18. Parker, R. I., Vannest, K. J., & Davis, J. L. (2011). Effect size in single-case research: a review of nine nonoverlap techniques. Behavior Modification, 35, 303–322.

    Article  PubMed  Google Scholar 

  19. Pustejovsky, J. E. (2016, November 3). What is Tau-U? Retrieved from

  20. Québec Ombudsman. (2012). Services provided to young people and adults with a pervasive developmental disorder. Retrieved from

  21. Rohatgi, A. (2017). Plot Digitizer [computer software]. Retrieved from

  22. Rogers, L. A., & Graham, S. (2008). A meta-analysis of single subject design writing intervention research. Journal of Educational Psychology, 100, 879–906.

    Article  Google Scholar 

  23. Shadish, W. R., & Sullivan, K. J. (2011). Characteristics of single-case designs used to assess intervention effects in 2008. Behavior Research Methods, 43, 971–980.

    Article  PubMed  Google Scholar 

  24. Sham, E., & Smith, T. (2014). Publication bias in studies of an applied behavior-analytic intervention: an initial analysis. Journal of Applied Behavior Analysis, 47, 663–678.

    Article  PubMed  Google Scholar 

  25. Shook, G. L. (2005). An examination of the integrity and future of the Behavior Analyst Certification Board® credentials. Behavior Modification, 29, 562–574.

    Article  PubMed  Google Scholar 

  26. Skinner, B. F. (1991). The behavior of organisms: an experimental analysis. Acton: Copley Publishing Group (Original work published 1938).

    Google Scholar 

  27. Vannest, K. J., & Ninci, J. (2015). Evaluating intervention effects in single-case research designs. Journal of Counseling & Development, 93, 403–411.

    Article  Google Scholar 

Download references


This research project was supported in part by a salary award (no. 30827) and a grant (no. 32612) from the Fonds de Recherche du Québec—Santé as well as a grant from the Canadian Institutes of Health Research (no. 136895) to the first author.

Author information



Corresponding author

Correspondence to Marc J. Lanovaz.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Lanovaz, M.J., Turgeon, S., Cardinal, P. et al. Using Single-Case Designs in Practical Settings: Is Within-Subject Replication Always Necessary?. Perspect Behav Sci 42, 153–162 (2019).

Download citation


  • AB design
  • Effect size
  • Error rate
  • Replication
  • Single-case design