Over two decades ago, Brown and Forsythe (B-F) (1974) proposed an
innovative solution to the problem of comparing independent normal means under
heteroscedasticity. Since then, their testing procedure has gained in popularity
and authors have published various articles in which the B-F test has formed the
basis of their research. The purpose of this paper is to point out, and correct, a
flaw in the B-F testing procedure. Specifically, it is shown that the approximation
proposed by B-F for the null distribution of their test statistic is inadequate. An
improved approximation is provided and the small sample null properties of the
modified B-F test are studied via simulation. The empirical findings support the
theoretical result that the modified B-F test does a better job of preserving the test
size compared to the original B-F tes