 (Cf. Niiniluoto 1980.) According to definition RP, it is meaningful to say that one theory \(g'\) satisfies better the cognitive goal of answering problem \(B\) than another theory \(g\). This is an absolute standard of scientific progress in the sense of Section 2.5. Definition EP shows how claims of progress can be fallibly evaluated on the basis of evidence: if \(ver(g\mid e) \lt ver(g'\mid e)\), it is rational to claim on evidence \(e\) that the step from \(g\) to \(g'\) in fact is progressive. This claim may of course be mistaken, since estimation of progress is relative to two factors: the available evidence \(e\) and the probability measure \(P\) employed in the definition of \(ver\). Both evidence \(e\) and the epistemic probabilities \(P(h_{i}\mid e)\) may mislead us. In this sense, the problem of estimating verisimilitude is as difficult as the problem of induction. 