• Options that facilitate error recovery should be on by default (e.g., checkpoint files, UNDO).
• Errors should be recognized and reacted to as soon as possible.
• Automatically correct minor user errors (and preferably point this out to the user)
• For major user errors, offer correction if possible.
• If not, provide error message.
  

Error messages

• Should explain
  • what the problem is
  • what the user can do to solve the problem (at least by examples)
• Should be formulated in terms of the user's task
• Should be polite; the word "unfortunately" should be avoided
  

Examples:  

Program errors

• In the case of a program crash, give users the opportunity to save their files, or save (checkpoint) files automatically.
• Allow users to abort programs, and to relaunch them.
•