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*Subject*: **Re: [office-formula] CHITEST definition**

*From*:**"Andreas J. Guelzow" <aguelzow@math.concordia.ab.ca>***To*: office-formula@lists.oasis-open.org*Date*: Mon, 12 Mar 2007 14:01:52 -0600

On Mon, 2007-12-03 at 19:10 +0100, Eike Rathke wrote: > Hi Andreas, > > On Friday, 2007-03-09 14:36:03 -0700, Andreas J. Guelzow wrote: > > > > > Furthermore, Ecma/Excel's definition of degrees of freedom looks weird, > > > > for rows>1 and cols>1 they say it would be (rows-1)*(cols-1). Why?!? > > > > > > Btw, OOo does the same. Probably because it was documented as such. > > > > Which test is CHITEST supposed to perform? > > > > In the cases of a test for independence or a test of homogeneity, these > > degrees of freedom make sense. (But we should have only one regular > > region). > > It claims to be an independence test. I know. But then it shouldn't use the "expected values" but calculate them from the row and column sums of the observed values. > On the other hand ... > > > In the case of a Goodness-of-Fit test one would have observed and > > expected frequencies (corresponding to each other) and the degree of > > freedom should be n-1. > > ... it gets two arrays passed, one of actual/observed values and one of > expected values. See also the current definition in the latest draft > document uploaded on Friday. If each column of observed values would > represent a different group, matching those of the expected values, what > would n-1 be then? So you really are performing several chi-sq tests in a single call? > For example: > > observed: x,y expected: X,Y =CHITEST(A1:B4;D1:E4) > > | A B C D E > -+-------------- > 1| x y X Y > 2| x y X Y > 3| x y X Y > 4| x y X Y > > How would the (rows-1)*(cols-1) fit in there? I can't see how that fits. Neter/Wasserman/Whitmore: When the sampled population has the probability distribution specified in H0 and the samepl size n is resonably large then X^2 is chi^2 distributed with k-m-1 degrees of freedom where k is the number of classes and m the number of parameters estimated from the sample data. Andreas > -- Andreas J. Guelzow, Professor Dept. of Mathematical & Computing Sciences Concordia University College of Alberta

**Follow-Ups**:**Re: [office-formula] CHITEST definition***From:*Eike Rathke <erack@sun.com>

**References**:**CHITEST definition***From:*Eike Rathke <erack@sun.com>

**Re: [office-formula] CHITEST definition***From:*Eike Rathke <erack@sun.com>

**Re: [office-formula] CHITEST definition***From:*Eike Rathke <erack@sun.com>

**Re: [office-formula] CHITEST definition***From:*"Andreas J. Guelzow" <aguelzow@math.concordia.ab.ca>

**Re: [office-formula] CHITEST definition***From:*Eike Rathke <erack@sun.com>

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