Amy Ferguson

Mentor: Dr. Mike Hixson
Research: Evaluating Autocorrelation in Single-Case Designs

Single-case experimental designs (SCEDs) are widely used in school psychology to evaluate interventions for students with attention-deficit/hyperactivity disorder (ADHD). However, the repeated-measures nature of SCEDs introduces autocorrelation, which can distort effect-size estimates and misrepresent intervention effectiveness. This study examines the presence and strength of lag-1 autocorrelation in SCEDs targeting academic engagement and disruptive behavior. Of the 469 articles, 117 studies met the inclusion criteria and were coded for study, case, and outcome-level variables. Using reproducible R scripts, we estimated autocorrelation for each time series and summarized outcomes with descriptive statistics. By quantifying autocorrelation across a large sample of SCEDs, this project aims to strengthen the methodological foundation of ADHD intervention research and promote more accurate, evidence-based decision-making in educational practice.