Dear Sebastian, Many researchers may transform the Pearson coefficients into Fisher's z scores first by using z <- 0.5*log((1+r)/(1-r)).
The standard errors of the Fisher's z scores are z.SE <- 1/sqrt(n-3) where n are the sample sizes (see http://en.wikipedia.org/wiki/Fisher_transformation). Either metagen {meta} or meta.summaries {rmeta} can be used to conduct a fixed- or a random-effects meta-analysis. -- --------------------------------------------------------------------- Mike W.L. Cheung Phone: (65) 6516-3702 Department of Psychology Fax: (65) 6773-1843 National University of Singapore http://courses.nus.edu.sg/course/psycwlm/internet/ --------------------------------------------------------------------- On Fri, Feb 13, 2009 at 7:11 PM, Sebastian Stegmann < stegm...@psych.uni-frankfurt.de> wrote: > Dear R-Community, > > I'm currently trying to find a way to conduct a meta-analysis in R. > I would like to analyze data from mostly-cross-sectional survey-studies. > The > effect sizes would be correlations. > > The R packages "meta" and "rmeta" are, as far as I can see, set up for > analysis with effect sizes for differences (i.e. comparison of the > means/odds-ratios of experimental and control group). > > Only the function "metagen" from the "meta"-package looks like it would > work > with correlations. The problem here: One would need to know the standard > error of the correlation. The SE is not usually reported in the studies I > have (only means, SDs and Alphas for the single variables). So the SE would > have to be calculated somehow... But maybe "metagen" is the wrong function > to start with in the first place? > > I'm wondering whether there might be anyone knowing how to conduct a > meta-analysis based on correlations in R? > > Thanks in advance > Sebastian > > P.S.: Of course, I'm dreaming of such a step-by-step-script like the > absolutely marvellous ones provided by Bliese for multilevel-analysis in R > :-) > > --------- > Dipl.-Psych. Sebastian Stegmann > Managing Editor, British Journal of Management > Goethe University > Institute of Psychology > Department of Social Psychology > Kettenhofweg 128 > 60054 Frankfurt am Main > Germany > http://www.sozialpsychologie.uni-Frankfurt.de/ > Phone: +49 (0) 69 / 798-23078 > Fax: +49 (0) 69 / 798-22384 > > ______________________________________________ > 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. > [[alternative HTML version deleted]] ______________________________________________ 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.
