A note on verisimilitude and relativization to problems

This note aims at critically assessing a little-noticed proposal made by Popper in the second edition ofObjective Knowledge to the effect that verisimilitude of scientific theories should be made relative to the problems they deal with. Using a simple propositional calculus formalism, it is shown that the relativized definition fails for the very same reason why Popper's original concept of verisimilitude collapsed-only if one of two theories is true can they be compared in terms of the suggested definition of versimilitude.This note was written when the author was visiting the Groupe de Recherche en Épistémologie Comparative (Université du Québec à Montréal).