Confirmation dialog · Plumeloft

Confirmation dialogs are pop-ups that pause the rest of the interface while keeping it visible. A well-judged dialog, used sparingly, protects people from losing work and makes a risky step feel deliberate. When used carelessly (asking twice before a harmless action, say), they train people to click through without reading.

Reserve them for choices that are hard to undo, or for warning someone before something irreversible happens. Because a dialog takes the whole screen focus, every unprompted appearance interrupts whatever the person was in the middle of.

That cost is paid every single time the dialog fires — not only on the occasions when the warning turns out to have been worth reading.