[R] Brown-Forsythe test of equality of MEANS

[Iasonas Lamprianou]

Dear friends,
two years ago (as I found on the web) Paul sent the following message but I was not able to find if he got an answer. Today I have the same question and it would be great if I could find out that this test has been implemented (somehow) in R. Please do not confuse it with the Brown-Forsythe test of equality of variances. Thank you:

I've been searching around for a function for computing the Brown-Forsythe F* statistic which is a substitute for the normal ANOVA F statistic for when there are unequal variances, and when there is evidence of non-normality. A couple of other people have asked this question, the responses I found have been:

    ?oneway.test

However, that function appears to use the Welch W statistic which, while good at handling unequal variances, is not as good as F* at handling non-normal distributions (or so my textbook tells me). So, two questions:

   1. Is there a function ready to use for calculating the Brown-Forsythe F*?
   2. If not, what do people use for checking the results of a (one-way) ANOVA when there is non-normality as well as non-constant variances? 

Thanks,

      
Dr. Iasonas Lamprianou


Assistant Professor (Educational Research and Evaluation)
Department of Education Sciences
European University-Cyprus
P.O. Box 22006
1516 Nicosia
Cyprus 
Tel.: +357-22-713178
Fax: +357-22-590539


Honorary Research Fellow
Department of Education
The University of Manchester
Oxford Road, Manchester M13 9PL, UK
Tel. 0044  161 275 3485
iasonas.lamprianou at manchester.ac.uk