Kirsh, D. and Maglio, P. (1994), On Distinguishing Epistemic from Pragmatic Action. Cognitive Science, 18: 513-549. https://doi.org/10.1207/s15516709cog1804_1
We present data and argument to show that in Tetris—a real-time, interactive video game—certain cognitive and perceptual problems are more quickly, easily, and reliably solved by performing actions in the world than by performing computational actions in the head alone. We have found that some of the translations and rotations made by players of this video game are best understood as actions that use the world to improve cognition. These actions are not used to implement a plan, or to implement a reaction; they are used to change the world in order to simplify the problem-solving task. Thus, we distinguish pragmatic actions—actions performed to bring one physically closer to a goal—from epistemic actions—actions performed to uncover informatioan that is hidden or hard to compute mentally.