I'm wondering what the rationale would be for using one-tailed
hypotheses on an F-ratio test of variances as a default. I notice
Excel does it this way. It's more conservative, to be sure, but why
not just lower the alpha level if that's what you're after? I don't
see what in this situation implies a one-tailed test ... you are
interested in equality of variances, not in one being greater than
the other. (?)
David Klein
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