UX Glossary · F
Feedback
The system telling the user that something registered, what is happening, and what the result was.
Feedback is the system’s response to a user’s action. Nielsen’s first heuristic, visibility of system status, is essentially a statement about it: keep users informed about what is going on, through appropriate feedback, within reasonable time.
The three moments
On input. Something must change within about 100 milliseconds of a press, or the user will press again. This is the origin of duplicate submissions.
During. Anything over roughly a second needs an indication that work is happening. Beyond about ten seconds it needs progress, ideally with an estimate, because an indefinite spinner is indistinguishable from a hang.
On completion. Say what happened. “Saved” is feedback; a screen that silently returns to a list is not, and the user is left to verify by inspection.
What makes it bad
Feedback in the wrong place, such as a confirmation at the top of a long page after the user pressed a button at the bottom. Feedback that disappears before it is read. And feedback that asserts something the system does not yet know, which is the risk with optimistic UI.
In practice
The absence of feedback is read as failure. A user who is not told an action worked will assume it did not and try again, which is how one request becomes three.