Dropbox is very detailed in their error alert for an incorrect email address, by requesting the missing character.
Good error messages reduce the user’s workload (both cognitive and physical)
Whenever possible, allow users to correct errors by editing their original action instead of having to do everything over again. For example, when presenting search results, show a search box with the user’s original query terms to facilitate revisions. If no hits were found, let users search a wider scope with a single click.
Another solution is to reduce the work of correcting the error. If possible, guess the correct action and let users pick it from a small list of fixes. For example, instead of just saying “city and zip code don’t match,” let users click on a button for the city that matches the zip code they entered.
Good error messages are a great opportunity to educate users
Let’s face it, users don’t read software/website documentation before using it. Users only read system documentation when they are in trouble. And when that happens, most likely, they will abandon the software/website whenever they can. However, people are particularly attentive when they want to recover from an error. If used correctly, error messages can be used as an educational resource to educate about the application’s hidden features. It could also be a good idea to add relevant links to additional background material or tutorials. But be cautious here, don’t overdo it. Keep the message brief and to the point.
Finally, Let users know you’re human.
Oftentimes, error messages can get very technical (read: intimidating) to a user. Moreover, some errors place blame on the user. As an important element of UX of interaction design, it’s important to write error messages in an understanding and friendly tone. It’s also important to keep the tone of voice consistent throughout the whole system.
What are some of the most frustrating errors you encounter? Let us know in a comment below.