Epistemic actions are defined as actions taken to alter the world so as to aid cognitive processes as opposed to pragmatic actions which alter the world in order to reach a desired goal. Epistemic actions are considered by many to be in itself cognitive despite the fact that they are external or extended cognition.
In the case of tetris, research has shown that humans perform many more rotations and translations than a computer would. In the case of a computer, or RoboTetris as the program used is called, the steps used are as follows :
• Create a representation of the current situation
• Break up the the total representation
• Find best position for falling shape
• Move into correct orientation
This model is fully sequential therefore a piece is only rotated of moved after a position has been located. This would mean that a bare minimum of moves is required and all moves are considered pragmatic actions.
Kirsh & Maglio deduced that human players, even expert players on par with RoboTetris, make use of epistemic actions. Many rotations and translations are usually made before a final location is chosen in order to aid cognition. Therefore the four steps mentioned above are not sequential in humans but are interleaved.
Human players use the extra rotations to :
• Discover new information earlier thereby saving time
• Eliminate the need for mental rotation
• Simplify matching of contours
Extra translations are used to avoid possible errors by translating to the wall and back a certain number of spaces to ensure the shape lines up before dropping.
Human players manipulate the situation since it is quicker and more reliable to physically alter the shape than to rely on mental rotation. Kirsh and Maglio found that epistemic actions are not a sign of a novice or inefficient player as was originally thought, but are a necessary part of the cognitive process.
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