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Talk:Significance of E. Coli Evolution Experiments (view source)
Revision as of 22:12, March 14, 2009
, 22:12, March 14, 2009→Unreferenced Claims
'''As with most statistical tests, the power of the chi-square test increases with a larger number of observations. If there are too few observations, it may be impossible to reject the null hypothesis even if it is false.'''"
'''As with most statistical tests, the power of the chi-square test increases with a larger number of observations. If there are too few observations, it may be impossible to reject the null hypothesis even if it is false.'''"
</blockquote> <ref>http://www.basic.northwestern.edu/statguidefiles/gf-dist_ass_viol.html</ref>--[[User:ElyM|ElyM]] 17:24, 14 March 2009 (EDT)
</blockquote> <ref>http://www.basic.northwestern.edu/statguidefiles/gf-dist_ass_viol.html</ref>--[[User:ElyM|ElyM]] 17:24, 14 March 2009 (EDT)
: Thanks for this really excellent contribution, ElyM. The only thing I'd like to add is in relation to your initial statement, "I do not believe that anyone has claimed that 'chi-square test p-values are always conservative'". The question of whether a test is conservative in a particular situation is probabilistic. One can determine whether a test is likely to generate a p-value which is too high in a particular situation (e.g. for a chi-squared test, when there are lots of small expected values) but one needs an exact test (such as an appropriate Monte Carlo randomisation test) to determine whether the p-value in any ''particular'' test is in fact excessively high.
: I hope careful reading of your very clear description will put SJohnson's mind at rest on this subject. [[User:FredFerguson|FredFerguson]] 18:11, 14 March 2009 (EDT)
== References ==
== References ==
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{{reflist}}