 The plurality of alternative probabilistic measures of relevance confirmation has prompted some scholars to be skeptical or dismissive of the prospects for a quantitative theory of confirmation (see, e.g., Howson 2000, 184–185, and Kyburg and Teng 2001, 98 ff.). However, as we will see shortly, quantitative analyses of relevance confirmation have proved important for handling a number of puzzles and issues that plagued competing approaches. Moreover, various arguments in the philosophy of science and beyond have been shown to depend critically (and sometimes unwittingly) on the choice of one confirmation measure (or some of them) rather than others (see Festa and Cevolani 2017, Fitelson 1999, Brössel 2013, Glass 2013, Roche and Shogenji 2014, Rusconi et al. 2014, and van Enk 2014).