Imagine using a note-taking app on your phone. You open this app, add some quick observations you did not want to forget, and close the app. In a couple of days, you open it again to review your notes and realise that the notes are gone. It turns out you had to select the "Save" option before closing the app. The app would not ask whether you want to do this. Which Nielsen's heuristic is violated on this occasion? Visibility of system status Match between system and real world Consistency and standards Error prevention