Creating Barrier-Free, Broadband Learning Environments
Appendix A: Evaluation Report
CANARIE Project: Broadband Access to Education
Ten Usability Heuristics
- Visibility of system status: The system should always keep users
informed about what is going on, through appropriate feedback within reasonable
time.
- Match between system and the real world: The system should speak
the users' language, with words, phrases and concepts familiar to the user,
rather than system-oriented terms. Follow real-world conventions, making information
appear in a natural and logical order.
- User control and freedom: Users often choose system functions by
mistake and will need a clearly marked "emergency exit" to leave the unwanted
state without having to go through an extended dialogue. Support undo and
redo.
- Consistency and standards: Users should not have to wonder whether
different words, situations, or actions mean the same thing. Follow platform
conventions.
- Error prevention: Even better than good error messages is a careful
design which prevents a problem from occurring in the first place.
- Recognition rather than recall: Make objects, actions, and options
visible. The user should not have to remember information from one part of
the dialogue to another. Instructions for use of the system should be visible
or easily retrievable whenever appropriate.
- Flexibility and efficiency of use: Accelerators -- unseen by the
novice user -- may often speed up the interaction for the expert user such
that the system can cater to both inexperienced and experienced users. Allow
users to tailor frequent actions.
- Aesthetic and minimalist design: Dialogues should not contain information
which is irrelevant or rarely needed. Every extra unit of information in a
dialogue competes with the relevant units of information and diminishes their
relative visibility.
- Help users recognize, diagnose, and recover from errors: Error messages
should be expressed in plain language (no codes), precisely indicate the problem,
and constructively suggest a solution.
- Help and documentation: Even though it is better if the system can
be used without documentation, it may be necessary to provide help and documentation.
Any such information should be easy to search, focused on the user's task,
list concrete steps to be carried out, and not be too large. (Nielsen, 1994)