Mayo sees the process of science as one of probing a claim for errors by subjecting it to "severe" tests. Here the severity of a test (vis-a-vis a hypothesis) is the sampling probability that the hypothesis <s>passes</s> fails to pass the test given that the hypothesis does not, in fact, hold true. (Severity is calculated holding the data fixed and varying hypotheses.) This is a process-centred view of science: it sees good science as founded on methodologies that rarely permit false hypotheses to pass tests.

Her pithy slogan for the contrast between her view and Bayesian epistemology is "well-probed versus highly probable". I expect that even she were willing to offer betting odds on the truth of a given claim, she would still deny that her betting odds have any relevance to the process of providing a warrant for asserting the claim.