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Benjamin Otto
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830

@benjamin-otto-1519
Last seen 8.2 years ago

Hey all,
1. For statistical tests there are usually minimal group sizes
recommended
for appropriate working. For a chi-square test as example the lower
level
was 10 obersvations in each field of the table, if I remember
correctly.
What about permutation tests? Is there some kind of minimal
recommendation
for group sizes? I can't find any hint on that.
2. As far as I understand the permutation p-value is given by the
quantile
describing the position of the native p-value in the permutation
p-value
distribution. So for 100 permutations and 5 values smaller than the
native
one the new p-value would be 0.05. What happens when the original
p-value is
the absolut minimum? Is such a thing like p-value equals zero defined?
3. Given a design of 3x3 samples (20 permutations), will the test
return
reasonable values? Doesn't look like it to me.
Best regards,
Benjamin Otto
======================================
Benjamin Otto
University Hospital Hamburg-Eppendorf
Institute For Clinical Chemistry
Martinistr. 52
D-20246 Hamburg
Tel.: +49 40 42803 1908
Fax.: +49 40 42803 4971
======================================
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