The big test of corroboration

This paper presents a new ‘discontinuous’ view of Popper’s theory of corroboration, where theories cease to have corroboration values when new severe tests are devised which have not yet been performed, on the basis of a passage from The Logic of Scientific Discovery. Through subsequent analysis and discussion, a novel problem for Popper’s account of corroboration, which holds also for the standard (‘continuous’) view, emerges. This is the problem of the Big Test: that the severest test of any hypothesis is actually to perform all possible tests (when ‘possible’ is suitably interpreted). But this means that Popper’s demand for ‘the severest tests’ amounts simply to a demand for ‘all possible tests’. The paper closes by considering how this bears on accommodation vs. prediction, with respect to corroboration.