Throwing the baby out with the bathwater: Pitfalls of misrepresenting single-case experimental designs

Document Type


Publication Date



statistical analysis; intervention, treatment effects, neuropsychological impairments; experimental design


Comments on an article by David Howard, Wendy Best, and Lyndsey Nickels. (see record 2015-06716-001). This paper, unfortunately, fell short of expectations on all three counts. Moreover, it has the potential to mislead present and future investigators about scientific method and philosophy that have been advancing behavioural science in communication disorders for several decades. First, the authors suggest that there are two major approaches that represent single-case experimental designs (SCED). The second approach discussed contrasts treated and untreated responses pre- and posttherapy evaluated through statistical analysis. As mentioned earlier, SCED methods for evaluating treatments are built around a number of basic tactics. The science of behaviour analysis continues to progress as investigators explore innovative designs that fit their phenomena of interest. But the task at hand is to develop and refine robust therapies. SCED offers a means to evaluate such therapies. It will take innovative clinical scientists and scientific clinicians to figure out how to make meaningful changes in the lives of persons with aphasia.