Single-case design effect-size distributions: Association with procedural parameters

Visual analysis is historically and conventionally used to draw conclusions about outcomes in single-case studies, but researchers are increasingly using effect sizes to supplement conclusions drawn about functional relations with additional information about magnitude of behavior change. However, there is limited information about the extent to which methodological choices (i.e., design type, measurement system) may impact the magnitude of behavior change. We conducted a systematic review of interventions conducted in elementary school classrooms to characterize effect sizes for engagement behaviors and challenging behaviors in those studies. We found that researchers most often used A-B-A-B and multiple baseline across-participants designs, that a variety of measurement systems were used for engagement but not challenging behavior, and that some variability in effect-size distributions can be explained by dependent variable type, design type, and measurement system. The empirically derived distributions from this study may be helpful for single-case researchers to contextualize past, ongoing, and future work related to engagement and challenging behavior. (PsycInfo Database Record (c) 2024 APA, all rights reserved).