[R] Mean Significance
Prof Brian Ripley
ripley at stats.ox.ac.uk
Wed Nov 5 16:57:53 CET 2003
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, ripley at stats.ox.ac.uk
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
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