This is a multiple comparisons problem, so no. You need to use TukeyHSD or the multcomp package. You can test contrasts via t-tests only if you select they before looking at the data.
Time to consult a good book on the subject? On Wed, 5 Nov 2003, Igor Roytberg wrote: > If you determine the means of x treatments and see that one is larger > than the others, can you use a sample normal to determine how > statistically significant the difference is? or would contrasts by a > better tool? How would one go about to do this in R? > > Thanks for any help (since R is new to me), -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help
