d1cf9e77_erience_in_ArnoLand__July_2009__Yes_but___
[Heuristic] Error prevention [Justification (From Nielsen)] Even better than good error messages is a careful design which prevents a problem from occurring in the first place. Either eliminate error-prone conditions or check for them and present users with a confirmation option before they commit to the action. [Yes but...] 
Here is a useless Heuristic. What is an error? One man's error is another man's exploration. Maybe you should enable errors?
User Experience in ArnoLand: July 2009
Yes but...