The purpose of this study is to present a set of empirically derived effect size distributions in order to provide field-based benchmarks for assessing the relative effects of interventions aimed at reducing challenging behavior or increasing engagement for young children with and without disabilities. We synthesized 192 single-case designs that represented data from 162 individuals and nine groups of individuals (e.g., classes) in 53 reports. We generated distributions of standardized mean difference and log-response ratio using 197 effect sizes for engagement and 146 effect sizes for challenging behavior. We examined benchmarks as a function of publication, disability, dependent variable (primary/secondary), and functional relation status and reported distributions separately by engagement and challenging behavior. Overall, the effect size distributions suggest considerable variability in the magnitude of change associated with school-based interventions for engagement and challenging behavior assessed in the context of single-case designs. Data suggest that expected magnitude of change for engagement and challenging behavior interventions may be difficult to predict and that study and effect size characteristics influence the variability of the distributions. Our results have direct implications for researchers relative to assessing the efficacy of interventions aimed at reducing challenging behavior or increasing engagement in young children with and without disabilities.

Interruption and redirection (IR) procedures involve systematically disrupting an undesirable behavior and prompting an individual to engage in an alternative behavior (e.g., Ahearn et al., 2007). These procedures have been frequently assessed for reducing stereotypy for autistic individuals. The purposes of this review were to determine (a) for whom and under what conditions physical and verbal IR procedures are assessed; (b) what outcomes are measured; (c) whether results vary by intervention characteristics, dependent variable types, design quality, and publication status; and (d) the extent to which generalization and maintenance outcomes are measured and show positive effects. IR interventions were moderately successful for reducing stereotypy but were less effective for improving appropriate vocalizations and functional engagement. Generalization and maintenance outcomes, when measured, were poor. Results indicate the need for alternative or augmentative procedures that focus on engagement in meaningful interactions and activities.

This review was designed to characterize current intervention research for increasing imitation for young children with disabilities. We identified 34 unique sources including assessments of different types of massed trial and embedded trial interventions. Across intervention types, when evaluated via the Single Case Analysis and Review Framework (SCARF), positive outcomes were more likely to occur when dependent variables were primary (i.e., not secondary to another dependent variable) and context-bound (i.e., collected during intervention sessions). When only primary variables from high-quality studies were considered, embedded trials more often resulted in functional relations. Recommendations for practice include using cues, prompts, and rewards for imitation; teaching imitation to toddlers; attending to imitation function; and teaching imitation in varied contexts.