From a statistical perspective the effect size (d or g) has the same meaning regardless of the study design. They stated that:Ī single systematic review can include studies that used independent groups and also studies that used matched groups. But is it necessary to take into account in the computation of the combined effect size that some studies followed a within-subject design or a between-subject design?Įdit: I maybe found something consistent with mdewey's answer to Jemma in Borenstein et al.
I am ok with that and correcting for research design is a part of the job. My question is : Do I need to do more than correcting for research design in order to combine my effect sizes? A similar question was already asked by Jemma ( A meta-regression with effect sizes from variously designed studies) and mdewey suggested to convert the effect size into the same scale. I know that I can correct standardized effect size for research design (e.g., Cumming, 2012, p. Meta-analyses can be performed when there are multiple scientific studies addressing the same question, with each individual study reporting measurements.
For my meta-analysis, I have some studies with a between-subject design and other with a within-subject design. Four metaanalytic approaches are reviewed which include Percentage of Nonoverlapping Data points (PND), the Busk and Serlin: Assumption models, ITSACORR, and Hierarchical Linear Modeling (HLM). Schlosser, PhD Northeastern University The question is no longer how meta-analysis of single-subject experimental research should be done, rather, of interest to this field, is how this should be accomplished. I learned that standardized measure of effect size like d and r are sensitive to resaerch design so that standardized effect size for within-subject design are usually larger than those for between-subject design in spite of the fact that the unstandardized effect sizes of both design are exactly the same (e.g., Baguley, 2009). Metaanalysis as an approach to ascertain EBPs is reviewed along with the inherent difficulties associated with single subject design research such as autocorrelations. 3, 375 378 Reply to Pennington Meta-analysis of single-subject research: how should it be done Ralf W. Meta-analysis of Single-subject Experimental Studies A review of meta-analyses of single-subject experimental designs: Methodological issues and practice S. I read some books (e.g., Cumming, 2012) and papers (e.g., Johnson & Eagly, 2000).