Reading notes: The Design of Everyday Things
I expected a book about doors and got a book about blame. The central argument is that when a person fails at a task, the failure is almost always in the design, and the reason we blame the person is that we cannot see the design.
Vocabulary worth stealing
- Affordance: what the object suggests you can do with it.
- Signifier: the visible cue about where the action happens.
- Mapping: how controls relate to the thing being controlled.
- Feedback: what tells you the action registered.
I have started using these in code review. When a command silently succeeds, I
say it lacks feedback. When a config key is named mode and accepts seven
strings, I say the signifier is doing no work.
The uncomfortable chapter
The chapter on human error is the one I keep thinking about. Norman argues that "human error" is a label we apply after the fact to hide the fact that the system had no tolerance for a normal human moment, like a lapse in attention at hour eleven of a shift.
In operations this is called "the operator clicked the wrong link", and the correct response is almost never more training. It is a confirmation step, a narrower permission, or a reversible action. Cheaper and more reliable than hoping people become different people.