Entertaining diverse assumptions about empirical research,
commentators give a wide range of verdicts on the NHSTP defence
significance. The null-hypothesis
significance-test procedure (NHSTP) is defended in a framework in
which deductive and inductive rules are deployed in theory
corroboration in the spirit of Popper's Conjectures
refutations (1968b). The defensible hypothetico-deductive
structure of the framework is used to make explicit the distinctions
between (1) substantive and statistical hypotheses, (2) statistical
alternative and conceptual alternative hypotheses, and (3) making
statistical decisions and drawing theoretical conclusions. These
distinctions make it easier to show that (1) H0 can be
true, (2) the effect size is irrelevant to theory corroboration, and
(3) “strong” hypotheses make no difference to NHSTP.
Reservations about statistical power, meta-analysis, and the Bayesian
approach are still warranted.