Models: Measuring or Cognitive Instruments?

A number of authors (Morgan, 1999; Boumans, 2005; Morrison, 2009; Massimi and Bhimji, 2015; Parker, 2017) have argued that models can be quite literally thought of as measuring instruments. I here challenge this view by reconstructing three arguments from the literature and rebutting them. Further, I argue that models should be seen as cognitive rather than measuring instruments, and that the distinction is important for understanding scientific change: Both yield two distinct sources of insight that mutually depend on each other, and should not be equated. In particular, we may perform the exact same actions in the laboratory but

conceive of them entirely differently by virtue of the models we endorse at different points in time.