“Good interaction design is about attending to every moment that passes between a person and the device (or system, or service) with which he or she is interacting. These moments can be explicit, as with gestures, taps, a button-click, or the completion of a form field. Or, these moments may be more elusive, such as a pause while you try and understand what is being asked of you or how to answer. It’s these internal conversations that users have at any given moment that often get overlooked.”
The theatre metaphor provides so much inspiration, insight and knowledge.