 There are four options for understanding incommensurability. Epistemicists hold that there is always some fact of the matter about which of the three relations \((\succ,\) \(\prec,\) \(\sim)\) holds, but that it is sometimes difficult or impossible to determine which one—thus incommensurability is merely apparent. They can model the decision problem in the standard way, but as a problem of uncertainty about values: one does not know whether one is in a state in which \(A \succcurlyeq B,\) but one assigns some probability to that state, and maximizes expected utility taking these kinds of uncertainties into account. Indeterminists hold that it is indeterminate which relation holds, because these relations are vague; thus incommensurability is a type of vagueness (Griffin 1986, Broome 1997, Sugden 2009, Constantinescu 2012). Incomparabilists hold that in cases of incommensurability, \(A\) and \(B\) simply cannot be compared (de Sousa 1974, Raz 1988, Sinnott-Armstrong 1988). Finally, those who hold that incommensurability is parity hold that there is a fourth relation than can obtain between \(A\) and \(B\): \(A\) and \(B\) are “on a par” if \(A\) and \(B\) can be compared but it is not the case that one of the three relations holds (Chang 2002a, 2002b, 2012, 2015, 2016). (Taxonomy from Chang 2002b; see also Chang 1997.)