Abstract

This paper reviews and develops the concept of “contextuality” whose profound significance—or lack thereof—was clarified especially by Detlef Dürr and his collaborators. In particular, we explore, in the context of a simple toy model of a measurement procedure described using Bohmian mechanics, the dependence of measurement outcomes on the (continuously variable) strength of the coupling between the system and measuring apparatus. This provides a revealing illustration of the fact that the outcomes of experiments may, and in general do, depend on details of the experiment other than simply the Hermitian operator which (as it is often misleadingly said) is “measured” in the experiment.