Nielsen’s usability principles and heuristics

1. Visibility of system status – always keep users informed about
   what is going l, through providing appropriate feedback within
   reasonable time
2. Match between system and the real world – speak the users’
   language, using words, phrases and concepts familiar to the user,
   rather than systemoriented terms
3. User control and freedom – provide ways of allowing users to
   easily escape from places they unexpectedly find themselves, by
   using clearly marked ‘emergency exits’
4. Consistency and standards – avoid making users wonder whether different words, situations, or actions mean the same thing
5. Help users recognize, diagnose, and recover from errors – use plain language to describe the nature of the problem and suggest a way of solving it
6. Error prevention - where possible prevent errors occurring in
   the first place
7. Recognition rather than recall – make objects, actions, and
   options visible 8. Flexibility and efficiency of use-provide
   accelerators that are invisible to lovice users, but allow more
   experienced users to carry out tasks more quickly 9. Aesthetic
   and minimalist design-avoid using information that is irrelevant
   or rarely needed
8. Help and documentation – provide information that can be easily
   searched and provides help in a set of concrete steps that can
   easily be followed

From: Preece, J., Rogers, Y., Sharp, H. (2002), Interaction Design: Beyond Human-Computer Interaction, New York: Wiley, p.27