 More prosaically, a measurement procedure can be considered accurate only if it doesn’t itself significantly alter the measurand. Measurement procedures usually involve some unavoidable change to the quantity being measured – placing a cold thermometer into a hot liquid will slightly cool the liquid, for example, but for most purposes this effect is negligible. The objection at hand is therefore that merely having the subject come to believe that they have some choice over these worlds and gambles will generally involve a substantial change to their beliefs – enough to undermine the accuracy of Ramsey’s procedure. For example, the process might alter the subject’s beliefs regarding the claim ‘Experimenters have the capacity to make it the case that \(\omega_1\) obtains if \(p\) is true, and \(\omega_2\) obtains otherwise’, with potentially many ripple on effects through to her other beliefs. Interestingly, Ramsey makes note of a similar problem for an alternative gambling-based measurement procedure (1926a, [FM] 170), but for unknown reasons does not discuss the worry as it arises for his own proposal.