Undo is useful only when it genuinely restores what the user lost. A confirmation dialog is useful only when it explains the consequence—not just “Are you sure?”
Consider a hypothetical media app where someone deletes a set of property photos. My starting point would be:
- Reversible removal: move files to trash, show a clear Undo action, and keep a discoverable recovery route after the toast disappears.
- Permanent or bulk deletion: show the affected names or count, what cannot be restored, and whether shared access will be affected before proceeding.
- Partial failure: report which files changed instead of claiming the entire operation succeeded.
The tricky case is shared assets: restoring a file may not reverse notifications or other effects that already happened.
W3C’s error-prevention guidance provides a useful reference for certain important submissions and changes to user-controllable stored data: reversal, checking, or confirmation. It does not mean adding a confirmation dialog to every routine edit.
Where do you draw the line between Undo, confirmation, and both? Would your answer change for one recoverable file versus a folder shared with a team?
Cover: original AI-generated conceptual illustration. The interfaces and recovery period shown are fictional, not a product demonstration.