Single-case experimental designs (SCEDs) are used to study the effects of interventions on the behavior of individual cases, by making comparisons between repeated measurements of an outcome under different conditions. In research areas where SCEDs …
A question came up on the R-SIG-meta-analysis listserv about whether it was reasonable to use the standardized mean difference metric for synthesizing studies where the outcomes are measured as proportions. I think this is an interesting question because, while the SMD could work perfectly fine as an effect size metric for proportions, there are also other alternatives that could be considered, such as odds ratios or response ratios or raw differences in proportions. Further, there are some situations where the SMD has disadvantages for synthesizing contrasts between proportions. Thus, it's a situation where one has to make a choice about the effect size metric, and where the most common metric (the SMD) might not be the right answer. In this post, I want to provide a bit more detail regarding why I think mean-variance relationships in raw data can signal that the standardized mean differences might be less useful as an effect size metric compared to alternatives.
Stay-play-talk (SPT) is a peer-mediated intervention which involves training peer implementers to stay in proximity to, play with, and talk to a focal child who has disabilities or lower social competence. This systematic review and meta-analysis …
A wide variety of effect size indices have been proposed for quantifying the magnitude of treatment effects in single-case designs. Commonly used measures include parametric indices such as the standardized mean difference, as well as non-overlap …
Single-case designs are a class of repeated measures experiments used to evaluate the effects of interventions for specialized populations, such as individuals with low-incidence disabilities. There has been growing interest in systematic reviews and …
I’m pleased to announce that my article “Using response ratios for meta-analyzing SCDs with behavioral outcomes” has been accepted at Journal of School Psychology. There’s a multitude of ways that you can access this work:
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 …
Methods for meta-analyzing single-case designs (SCDs) are needed to inform evidence-based practice in clinical and school settings and to draw broader and more defensible generalizations in areas where SCDs comprise a large part of the research base. …
I’m very happy to share that my article “Procedural sensitivities of effect sizes for single-case designs with directly observed behavioral outcome measures” has been accepted at Psychological Methods. There’s no need to delay in reading it, since you can check out the pre-print and supporting materials.
One of the papers that came out of my dissertation work (Pustejovsky, 2015) introduced an effect size metric called the log response ratio (or LRR) for use in meta-analysis of single-case research—particularly for single-case studies that measure behavioral outcomes through systematic direct observation.