Hi, thanks for the references I will try the sensitivitiy-analysis in R and try out winbugs if that does not work (little afraid of switching programmes).
I also had an idea for a reasonable estimate of the correlations. Some studies report both results from paired t-tests and means and SDs, and thus allow to calculate two estimates for d one based on M and SD alone the other on t. The difference between the two estimates should be systematically related to the correlations of measures. I will keep you posted, if I have a solution or hit a wall. efachristo and dank je wel! Gerrit On 12.06.2010, at 15:59, Viechtbauer Wolfgang (STAT) wrote: > Dear Gerrit, > > the most appropriate approach for data of this type would be a proper > multivariate meta-analytic model (along the lines of Kalaian & Raudenbush, > 1996). Since you do not know the correlations of the reaction time > measurements across conditions for the within-subject designs, a simple > solution is to "guestimate" those correlations and then conduct sensitivity > analyses to make sure your conclusions do not depend on those guestimates. > > Best, > > -- > Wolfgang Viechtbauer http://www.wvbauer.com/ > Department of Methodology and Statistics Tel: +31 (0)43 388-2277 > School for Public Health and Primary Care Office Location: > Maastricht University, P.O. Box 616 Room B2.01 (second floor) > 6200 MD Maastricht, The Netherlands Debyeplein 1 (Randwyck) > > > ----Original Message---- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On > Behalf Of Gerrit Hirschfeld Sent: Saturday, June 12, 2010 12:45 > To: r-help@r-project.org > Subject: [R] meta analysis with repeated measure-designs? > >> Dear all, >> >> I am trying to run a meta analysis of psycholinguistic reaction-time >> experiments with the meta package. The problem is that most of the >> studies have a within-subject designs and use repeated measures ANOVAs to >> analyze their data. So at present it seems that there are three >> non-optimal ways to run the analysis. >> >> 1. Using metacont() to estimate effect sizes and standard errors. But as >> the different sores are dependent this would result in biased estimators >> (Dunlap, 1996). Suppose I had the correlations of the measures (which I >> do not) would there by an option to use them in metacont() ? >> >> 2. Use metagen() with an effect size that is based on the reported F for >> the contrasts but has other disadvantages (Bakeman, 2005). The problem I >> am having with this is that I could not find a formular to compute the >> standard error of partial eta squared. Any Ideas? >> >> 3. Use metagen() with r computed from p-values (Rosenthal, 1994) as >> effect size with the problem that sample-size affects p as much as effect >> size. >> >> Is there a fourth way, or data showing that correlations can be neglected >> as long as they are assumed to be similar in the studies? >> Any ideas are much apprecciated. >> >> best regards >> Gerrit >> >> ______________________________ >> Gerrit Hirschfeld, Dipl.-Psych. >> >> Psychologisches Institut II >> Westfälische Wilhelms-Universität >> Fliednerstr. 21 >> 48149 Münster >> Germany >> >> psycholinguistics.uni-muenster.de >> GerritHirschfeld.de >> Fon.: +49 (0) 251 83-31378 >> Fon.: +49 (0) 234 7960728 >> Fax.: +49 (0) 251 83-34104 >> >> ______________________________________________ >> R-help@r-project.org mailing list >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide >> http://www.R-project.org/posting-guide.html >> and provide commented, minimal, self-contained, reproducible code. ______________________________ Gerrit Hirschfeld, Dipl.-Psych. Psychologisches Institut II Westfälische Wilhelms-Universität Fliednerstr. 21 48149 Münster Germany psycholinguistics.uni-muenster.de GerritHirschfeld.de Fon.: +49 (0) 251 83-31378 Fon.: +49 (0) 234 7960728 Fax.: +49 (0) 251 83-34104 ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
