 Recently, however, Koscholke and Schippers (2015) have noted a counterintuitive feature of \(C_1\): that it is impossible to increase a set’s degree of coherence by adding further propositions to the set. They also show that according to a more sophisticated relative overlap measure which avoids this issue no set’s degree of coherence exceeds the degree of coherence of its maximally coherent subset. On the other hand, they also prove in a later article, in collaboration with Stegman, that there is a further relative overlap measure which avoids both these problems and which therefore in their view re-establishes relative overlap as a candidate for a proper formalization of coherence (Koscholke, Schippers and Stegman, 2019).