"Help users recognize, diagnose and recover from errors: Error messages should be expressed in plain language (no codes)".
I'm using icq v 4.1 and increasingly more often while instant messaging; I'm suddenly unable to send off messages. The error message that appears explains the problem only by a code. That’s not what I want, I want a brief, easy to understand message that explains what happened. Therefore, the word on my mind right now is heuristics.
According to Nielsens website, new findings on usability guidelines for websites is to be presented at the Usability 2005 conference, in Stockholm among other places.