Peter Dalgaard wrote:
> Mike Lawrence wrote:
>> Looks like that code implements a non-exhaustive variant of the
>> randomization test, sometimes called a permutation test.
>
> Isn't it the other way around? (Permutation tests can be exhaustive
by looking at all permutations, if a randomization test did that, then
it wouldn't be random.)
Eugene Edgington wrote an early book (1980) on this subject called
"Randomization tests", published by Dekker. As far as I remember, he
differentiates between "Systematic permutation" tests where one looks at
all possible permutations. This is of course prohibitive for anything
beyond trivially small samples. For larger samples he uses what he
calls "Random permutations", where a random sample of the possible
permutations is used.
Tom
Peter Dalgaard wrote:
Mike Lawrence wrote:
Looks like that code implements a non-exhaustive variant of the
randomization test, sometimes called a permutation test.
Isn't it the other way around? (Permutation tests can be exhaustive by
looking at all permutations, if a randomization test did that, then it
wouldn't be random.)
--
+----------------------------------------------------------------+
| Tom Backer Johnsen, Psychometrics Unit, Faculty of Psychology |
| University of Bergen, Christies gt. 12, N-5015 Bergen, NORWAY |
| Tel : +47-5558-9185 Fax : +47-5558-9879 |
| Email : bac...@psych.uib.no URL : http://www.galton.uib.no/ |
+----------------------------------------------------------------+
______________________________________________
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.
