Statistical Significance

Chris, you stated in a couple of places that a is the p-value.  Is that not what you meant?

a is the specified significance level for the experiment - the value that is commonly set to 0.05. I see I have described it parenthetically above as "in other words the p value," which I can see is confusing. I should have said "the p value for significance" or something like that.

And thank you for raising this, because it's made me realise that I have recently erred in using a p value rather than the significance level in another thread - the one on Louie Savva's thesis. In the following post, the power value should have been recalculated so that it was based on the p value rather than on 0.05 (I think this reduces the "psi probability" to 90%* rather than 94%, but I'll check that as soon as I have a chance):
https://psiencequest.net/forums/thread-l...2#pid30962

(* Edit, on reflection I think it's fairer to use the 0.05 significance level and not recalculate the power. That gives 85%, compared with 94% if the study had been properly powered. Fortunately that's about the same answer obtained by calculating directly the probability of the observed hit rate under psi and no-psi hypotheses.)