User engineering principles for interactive systems

TLDR

The feel of an interactive system is analogous to music, experienced over time, requiring users to abstract its structure from details and yielding a sense of naturalness when successive actions follow a self‑consistent pattern. A skilled composer can craft a new pattern that, after a few listenings, feels so natural that observers wonder why it was never done before.

Abstract

The 'feel' of an interactive system can be compared to the impressions generated by a piece of music. Both can only be experienced over a period of time. With either, the user must abstract the structure of the system from a sequence of details. Each may have a quality of 'naturalness' because successive actions follow a logically self-consistent pattern. Finally, a good composer can write a new pattern which will seem, after a few listenings, to be so natural the observer wonders why it was never done before.