Recently, single-case research has been recognized as an approach for establishing evidence-based practices (Horner et al., 2005;Kratochwill et al., 2010). As the implications of single-case research become increasingly far reaching and focused on socially meaningful outcomes, single-case researchers are expected to not only document a functional relation between manipulating the independent variable and change in the dependent variable, but also to demonstrate that the independent variable under investigation is perceived as socially acceptable and feasible by typical stakeholders (Horner et al., 2005). In other words, single-case researchers may be able to demonstrate sizable effects, but if the intervention is not well received by educators, students, and their families, it is unlikely that the intervention will be adopted or maintained.Applied behavior analysis, and more recently positive behavior support, emphasize the importance of valued clinical outcomes as an essential feature of behavioral research and practice (e.g., Baer, Wolf, & Risley, 1968;E. G. Carr et al., 2002). In his seminal article addressing the importance of social validity, Montrose Wolf (1978) argued that making socially meaningful contributions through research involves investigating the relationship between what is objectively measured and how it is perceived by its consumers. In the 1970s, the practice of asking participants to report what they think was novel and counterintuitive to the singular focus on directly observable and measurable behaviors that was typical in applied behavior analytic research. Nonetheless, it had become apparent that if practices were going to be adopted, they needed to be not only effective but also well regarded. To avoid making assumptions about the subjective judgments of consumers, researchers needed to begin using methods to assess social validity. Wolf (1978) therefore outlined what he termed three levels of social validity: (a) Are the specific behavioral goals really what society wants? (b) Do the ends justify the means? That is, do the participants, caregivers and other consumers consider the treatment procedures acceptable? and (c) Are the consumers satisfied with the results? . . . including any unpredicted ones? (p. 207) 490809R SEXXX10.