Epistemic tool implementation in science classrooms builds on the practice turn unique to the current era of science education reform. In this essay, we consider how professional science engage with objects that serve epistemic goals. We also consider the challenge of adapting epistemic tools to a variety of science learning contexts.A tool or machine is not simply a simple or complex physical object having its own physical properties and effects … For it says something, to those who understand it, about operations of use and their consequences.… These objects are so intimately bound up with interests, occupations and purpose that they have an eloquent voice. (John Dewey, 1938, p. 80)