Dear Kathryn I think that the author of metafor has addressed this
http://www.metafor-project.org/doku.php/tips:comp_two_independent_estimates The other tips on that site are well worth reading too. On 29/07/2016 14:44, Morris, Kathryn wrote:
I am running a meta-analysis using metafor and getting what seem to be conflicting results. #analysis with species moderator cropMeta.species<-rma(cropyi, cropvi, data=dataCropMeta, mods=~dataCropMeta$species - 1, method="HE") The output for the analysis using species as a moderator shows estimates for the seven species in my data set, and makes sense. #subset analysis with B oleraceae cropMeta.species.b.oleracea<-rma(cropyi, cropvi, data=dataCropMeta, subset=(species=="B. oleracea"), method="HE") Then when I start to plot the results and use separate analyses for each species in order to get the coef and variances for plotting the subgroups I get different estimates. The estimates for most subgroups are almost identical in both analyses, but one of them is 5.922 in the analysis with species as a moderator, and 7.0139 in the subset analysis for only that species. Why are the estimates different? If they should be different, then which analysis is producing the correct estimates? I'm happy to provide the data and R scripts if that would help. many thanks, Kathryn --------------------------------- Dr. Kathryn Morris Assistant Professor, Biology Xavier University 3800 Victory Parkway Cincinnati, OH 45207 Office: (513) 745-3554 ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
-- Michael http://www.dewey.myzen.co.uk/home.html ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
