In dance, there is a practice called "marking". When dancers mark, they execute a dance phrase in a simplified, schematic or abstracted form. Based on our interviews with professional dancers in the classical, modern, and contemporary traditions, it is fair to assume that most dancers mark in the normal course of rehearsal and practice. When marking, dancers user their body-in-motion to represent some aspect of the full-out phrase they are thinking about. Their stated reason for marking is that it saves energy, avoids strenuous movement such as jumps, and sometimes it facilitates review of specific aspects of a phrase, such as tempo, movement sequence, or intention, all without the mental and physical complexity involved in creating a phrase full-out. It facilitates real-time reflection.
If you're a designer of gestural interfaces, you likely spend a lot of time marking, using your body to think about the interactions you have with a screen or camera or any machine space. This paper can give you a framework for thinking about marking and argues for the importance of going beyond 'imagining' interaction.
The opportunity to reconceptualize things is something that mental simulations does not offer. It is a major reason "externalizing" what is in mind is a more powerful strategy than working with things in the mind alone.
