The review examined over 400 published SCED studies and found that most were generally consistent with contemporary standards for experimental quality. Smith highlights the strengths of SCEDs as flexible, rigorous methods for evaluating interventions when large group studies are impractical, while also identifying ongoing challenges in measurement, sampling, and data analysis. Visual analysis remained the most common analytic approach, despite increasing use of statistical methods. Overall, the paper provides an important methodological overview of SCED research and offers practical guidance for improving the design, conduct, and evaluation of single-case studies.