A Primer on Single-Case Research Designs: Contemporary Use and Analysis.

The overarching purpose of this article is to provide an introduction to the use of rigorous single-case research designs (SCRDs) in special education and related fields. Authors first discuss basic design types and research questions that can be answered with SCRDs, examine threats to internal validity and potential ways to control for and detect common threats, and provide guidelines for selection of specific designs. Following, contemporary standards regarding rigor, measurement, description, and outcomes are presented. Then, authors discuss data analytic techniques, differentiating rigor, positive outcomes, functional relations, and magnitude of effects.

Systematic Review of Problem Behavior Interventions: Outcomes, Demographics, and Settings.

Interventions designed to decrease problem behavior for students with ASD are critical and may be differentially important for students from minority groups as those students tend to be assigned more negative outcomes related to problem behavior (e.g., suspensions). School-based interventions intended to decrease problem behavior for individuals with ASD were reviewed; 46 articles including 84 single case designs and 87 participants were analyzed regarding participant demographics, settings and implementers, intervention components, and study characteristics. We assessed outcomes for 55 demonstration designs with adequate rigor. Most research was conducted with students in segregated settings and, although race and ethnicity were rarely reported, proportions were different from other reviews in that children from some minority groups were overrepresented.

Single-case synthesis tools II: Comparing quantitative outcome measures.

Varying methods for evaluating the outcomes of single case research designs (SCD) are currently used in reviews and meta-analyses of interventions. Quantitative effect size measures are often presented alongside visual analysis conclusions. Six measures across two classes-overlap measures (percentage non-overlapping data, improvement rate difference, and Tau) and parametric within-case effect sizes (standardized mean difference and log response ratio [increasing and decreasing])-were compared to determine if choice of synthesis method within and across classes impacts conclusions regarding effectiveness. The effectiveness of sensory-based interventions (SBI), a commonly used class of treatments for young children, was evaluated. Separately from evaluations of rigor and quality, authors evaluated behavior change between baseline and SBI conditions. SBI were unlikely to result in positive behavior change across all measures except IRD. However, subgroup analyses resulted in variable conclusions, indicating that the choice of measures for SCD meta-analyses can impact conclusions. Suggestions for using the log response ratio in SCD meta-analyses and considerations for understanding variability in SCD meta-analysis conclusions are discussed.

Single-case synthesis tools I: Comparing tools to evaluate SCD quality and rigor.

Tools for evaluating the quality and rigor of single case research designs (SCD) are often used when conducting SCD syntheses. Preferred components include evaluations of design features related to the internal validity of SCD to obtain quality and/or rigor ratings. Three tools for evaluating the quality and rigor of SCD (Council for Exceptional Children, What Works Clearinghouse, and Single-Case Analysis and Design Framework) were compared to determine if conclusions regarding the effectiveness of antecedent sensory-based interventions for young children changed based on choice of quality evaluation tool. Evaluation of SCD quality differed across tools, suggesting selection of quality evaluation tools impacts evaluation findings. Suggestions for selecting an appropriate quality and rigor assessment tool are provided and across-tool conclusions are drawn regarding the quality and rigor of studies. Finally, authors provide guidance for using quality evaluations in conjunction with outcome analyses when conducting syntheses of interventions evaluated in the context of SCD.