Re: Levene test with large sample

Posted by Art Kendall on Mar 24, 2007; 1:45pm
URL: http://spssx-discussion.165.s1.nabble.com/Levene-test-with-large-sample-tp1074661p1074663.html

I would recommend using the separate variances estimate to report.

The observed difference is not not readily attributable to random
variation among samples from a common pop. i.e. the difference is
"statistically significant".

However, you characterize the difference as trivial, this should also be
reported.

It is difficult to comment further without more information about the
study design, definitions of the DV and IV, and the decision this
analysis was dine in support of.

Art Kendall
Social Research Consultants


Stephen Salbod wrote:

> Good Evening Everyone,
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>
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> I hope someone will guide me around this simple problem that fell in front
> of me today.
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> Which t test do I want to report?
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> I have two groups:
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> Group1   n= 1,512       M=2.5668           SD1=.80339
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> Group2   n=    273       M=2.3187           SD2=.96877
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> Levene's Test for Equality of Variance F= 27.531, p<.0001.
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> 1) Equal Variances Assumed t(1783) = 4.542, p <.001.
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> 2) Equal Variances NOT Assumed t(342.79) = 3.991.
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> The large N has created a statistically significance difference out of a
> trivial difference; furthermore, the variances between the groups are
> statistically different.
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> Can Levene's result be ignored because of the large sample or is it
> recommended that I report t test #2?
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> I would appreciate any suggestions and, if possible, references on this
> problem.
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> I thank you in advance.
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> Stephen Salbod, Pace University
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>