error messages

A good error message has three parts: The problem – explains that an error has happened; The cause – explains what caused the problem; The solution – explains how to overcome the problem. After you ensure your message contains all these three parts, its time to review it. You need to edit it to ensure it: Is user centred – avoid jargon and words your audience will have an hard time understanding; Is direct – as William Strunk said, “Put statements in positive form....

There is, however, old wisdom — perhaps from an earlier version of the Mac HIG — that says how to create error messages: they should be of the form “Can’t x because of y.” They may optionally include additional detail and/or recovery steps. “Can’t x because of y. Something is true. Try a thing.” A similar form is this: “Noun can’t x because y.” (As in “‘Downloaded.app’ can’t be opened because it is from an unidentified developer....