Hi, Anova compare the means of more than two groups, in your case anova test H0 hypothisis
H0: means(control)=mean(tread1)=mean(tread2)=mean(tread3), if there is at least one différence, you can identify the mean difference between groups by using post hoc test to testing your B suggestion. Regrads ML Le 29/11/11 11:49, syrvn a écrit : > Hello, > > > imagine the following experimental design: > > Group - Value > > control - 5 > control - 6 > control - 5 > > treated1 - 8 > treated1 - 9 > treated1 - 9 > > treated2 - 15 > treated2 - 16 > treated2 - 15 > > treated3 - 25 > treated3 - 30 > treated3 - 28 > > > What I like to know is if I apply an ANOVA to this data and choose the > control group as the reference group (using the relevel function) > what groups exactly are compared? Are only all treated groups 1, 2, 3 tested > against the control group or are all possible combinations tested? > > What is compared? > > A) Testing: control vs treated1; control vs treated2; control vs treated3; > > or > > B) Testing: control vs treated1; control vs treated2; control vs treated3; > > treated1 vs treated2; treated1 vs treated3; treated2 vs > treated3; > > > Cheers > > > > > > -- > View this message in context: > http://r.789695.n4.nabble.com/quick-ANOVA-question-tp4118724p4118724.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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. > -- #################################### Mohamed Lajnef,IE INSERM U955 eq 15# P?le de Psychiatrie # H?pital CHENEVIER # 40, rue Mesly # 94010 CRETEIL Cedex FRANCE # mohamed.laj...@inserm.fr # tel : 01 49 81 32 79 # Sec : 01 49 81 32 90 # fax : 01 49 81 30 99 # #################################### [[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.
