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welchanova

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Welch ANOVA Test for Unequal Variances.

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The ANOVA F-test to compare the means of k normally distributed populations is not applicable when the variances are unknown, and not known to be equal. A spacial case, k=2, is the famous Behrens-Fisher problem (Behrens, 1929; Fisher, 1935). Welch (1951) test was proposed to fill this void, a generalization to his 1947 previous paper (Welch, 1947).

Syntax: function welchanova(x,alpha)

Inputs:
x – data nx2 matrix (Col 1 = data; Col 2 = sample code)
alpha - significance level (default=0.05)

Outputs:
- Summary statistics from the samples
- Decision on the null-hypothesis tested

Comments and Ratings (3)

Is there a way to see which groups are significantly different?

Hi!
I am just wondering if it is possible to use your program as 2-way anova for unequal variances?
Thanks!

gargouri

Hello
I had used your code of Levene test :)
and I found that samples have not an homogenious variance so I can not use ANOVA.
So I would like to know instead of ANOVA if we can use Welch ANOVA since the distribution not normal?
Thank you

Updates

1.1

It was added an appropriate format to cite this file.

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