 In answering this question, philosophers have benefited from studying the various senses of the term “measurement accuracy” as used by practicing scientists. At least five different senses have been identified: metaphysical, epistemic, operational, comparative and pragmatic (Tal 2011: 1084–5). In particular, the epistemic or “uncertainty-based” sense of the term is metaphysically neutral and does not presuppose the existence of true values. Instead, the accuracy of a measurement outcome is taken to be the closeness of agreement among values reasonably attributed to a quantity given available empirical data and background knowledge (cf. JCGM 2012: 2.13 Note 3; Giordani &amp; Mari 2012; de Courtenay and Grégis 2017). Thus construed, measurement accuracy can be evaluated by establishing robustness among the consequences of models representing different measurement processes (Basso 2017; Tal 2017b; Bokulich 2020; Staley 2020).