 On Healey’s pragmatist approach, an application of the Born rule directly specifies probabilities for claims about the values of physical magnitudes (dynamical variables of classical physics as well as new variables such as strangeness and color): it does not explicitly specify probabilities for measurement outcomes. But the Born rule is legitimately applied only to claims with sufficiently well-defined content. The content of a claim about the value of a physical magnitude on a system depends on how the system interacts with its environment. Quantum theory may be used to model such interaction. Only if a system’s quantum state is then stably decohered in some basis (see entry on  the role of decoherence in quantum mechanics)  do claims about the value of the associated “pointer magnitude” acquire a sufficiently well-defined content to license application of the Born rule to them. Because of this restriction on its legitimate application, the Born rule may be consistently applied to claims of this form (not just to claims about the outcomes of measurements) without running afoul of no-go results such as that of Kochen and Specker (see entry on  the Kochen-Specker theorem).