You're right Ivor. You don't test a physicist to see whether the physics is correct. In science, what one tests is a particular claim. I think my experiment was a completely valid test of the specific claim that a reputable astrologer can accurately describe a person based on knowing their gender, birth date, birth time, and birth place. Our test subjects clearly could not recognize themselves in the profiles provided by the astrologer when they were presented "blindly" (i.e. without knowing which one is "correct"). The comment from the student about "not being good at astrology" was a little funny (IMHO) because, for the claim to be correct, the person being profiled should not have to know anything at all about astrology - let alone be "good at it". Modern science has built airships that can safely keep me aloft even though I know nothing about how they work - let alone am any good at flying one. :)