On Sun, 27 Aug 2000, Rich Ulrich wrote:
> On 24 Aug 2000 13:30:02 -0700, [EMAIL PROTECTED] (dennis roberts) wrote:
>
> > in some cases ... chi square test statistics require using ONLY 1 tail ...
> > of the relevant chi square distribution ... but some cases require using a
> > two tailed approach ...
>
> I have had a few instances where I looked at the left-tail (near zero)
> rather than the right-tail of chi square. There were very special
> circumstances, requiring careful thought as to whether the test was
> fair and justified. Off hand, I don't recall *ever* wanting to
> combine those left and right tails for a "two tailed approach." They
> address separate questions, don't they?
If you are dealing with a one-sample test and concerned with whether the
variance is _different_ from some specific value, one would use a
two-tailed chi-squared test... at least I would...
Bill
__________________________________________________________________________
William B. Ware, Professor and Chair Educational Psychology,
CB# 3500 Measurement, and Evaluation
University of North Carolina PHONE (919)-962-7848
Chapel Hill, NC 27599-3500 FAX: (919)-962-1533
http://www.unc.edu/~wbware/ EMAIL: [EMAIL PROTECTED]
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