1.
Error Messages

2.
Don't Accuse the User

3.
If it's anyone's fault, it's yours

4.
Speak the user's language

5.
Speak the user's language

6.
Identify the specific problem

7.
If possible, fix the problem

8.
If possible, fix the problem

9.
Don't just turn text red

10.
Give clear instructions

11.
Let them know you take it seriously

12.
Further Reading
“10 Tips on Writing Hero-worthy Error Messages” Treehouse
http://blog.teamtreehouse.com/10-tips-on-writing-hero-worthy-error-messages
“Avoid Being Embarrassed by Your Error Messages,” UXMatters
http://www.uxmatters.com/mt/archives/2010/08/avoid-being-embarrassed-
by-your-error-messages.php
“A More Useful 404,” A List Apart
http://alistapart.com/article/amoreuseful404
“Non-Fatal Errors: Creating Usable, Effective Error Messages,” Writers UA
http://www.writersua.com/articles/message/index.html