[R] paired t-test vs pairwise t-test

Jack Tanner ihok at hotmail.com
Thu Aug 19 20:48:38 CEST 2004

From: Rolf Turner <rolf at math.unb.ca>
>No.  The pairwise.t.test() function (according to the help
>file) does a multiplicity of t-tests, on more than two
>samples, adjusting the p-value to compensate for the
>multiplicity by various methods.

Thank you, Rolf, that's helpful. So pairwise.t.test() is used for comparison 
of more than two means. I did, indeed, confuse it with t.test(paired=TRUE). 
But the documentation, which I valiantly tried to make sense of BEFORE 
asking my stupid question, is not clear enough for this particular idiot. 
Might I suggest that the documentation be altered? It could use an example 
(as in, real-life applied statistical problem) of when pairwise.t.test() 
ought to be used, and why t.test(paired=TRUE) would be inappropriate in that 
context; it could also use a reference to some published paper, website or 
some such that explains the rationale and correct procedure for using this 

Thanks again for your clairvoyance.

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