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)
x – data nx2 matrix (Col 1 = data; Col 2 = sample code)
alpha - significance level (default=0.05)
- Summary statistics from the samples
- Decision on the null-hypothesis tested
Is there a way to see which groups are significantly different?
I am just wondering if it is possible to use your program as 2-way anova for unequal variances?
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?
It was added an appropriate format to cite this file.