Abstract

In this article I explain why scientists cannot always resolve their disagreements about experiments even if they do not hold conflicting theoretical assumptions, and how incommensurability in experiments can occur even if experiments are not deeply encumbered by theoretical assumptions. On the basis of recent discoveries in cognitive psychology and an extended analysis of a historical case, I explore a cognitive mechanism that may generate incommensurability in experiment appraisal. I find that, because of the involvement of goal-derived categories, incommensurability in experiments may result from the conflict of goals that scientists pursue in their researches, from the differences of goal-derived classification schemata that they employ in analyzing experiments, and from discrepancies between skills that they have developed in their practices. This account differs from the conventional interpretation of Kuhn’s thesis, which attributes the cause of incommensurability solely to theoretical differences. In the conclusion, I further discuss the implications of this new account of incommensurability for both philosophical and historical studies of science.