Heuristic Evaluation
Traditional Heuristics
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)
The heuristic evaluation of HCI was first
introduced in 1990 by Jakob Nielsen and Rolf
Molich. Their evaluation method consisted of
The advantages of this evaluation method are
having three to five expert users (people who is
many. It is a relatively inexpensive, easy and
familiar with the system) compare the system to a
quick, and can be used to evaluate non-finished
set of common usability principles known as the
products (Nielson 1990). This makes heuristics a
heuristics. The evaluator rates the system on a one
choice form of evaluation, used often in when
to five scale, one indicating that the system does
testing interfaces.
not adhere to the principle, and 5 indicating that the
system does adhere. The generally accepted
Ambient Interface Heuristics
heuristics used for this evaluation, as defined by
Jakob Nielsen, are the following:
While the traditional heuristics are effective in
Visibility of system status - The system should always keep evaluating many user interfaces, some of these
users informed about what is going on, through appropriate heuristics do not apply to ambient displays, while
feedback within reasonable time.
other key design principles for ambient displays are
Match between system and the real world - The system
missing from the heuristics. This is due to the
should speak the users' language, with words, phrases and
different nature of ambient displays. In 2003, a
concepts familiar to the user, rather than system-oriented
terms. Follow real-world conventions, making information new revised set of 12 heuristics were developed to
appear in a natural and logical order.
accommodate the special needs of ambient
User control and freedom- Users often choose system
displays. The following are revised heuristics,
functions by mistake and will need a clearly marked
including descriptions of the new heuristics:
"emergency exit" to leave the unwanted state without having
to go through an extended dialog. Support undo and redo.
Sufficient information design - The display should
Consistency and standards - Users should not have to
wonder whether different words, situations, or actions mean
be designed to convey “just enough” information. Too
the same thing. Follow platform conventions.
Error prevention - Even better than good error messages is much information cramps the display, and too little
a careful design which prevents a problem from occurring in makes the display less useful.
the first place. Either eliminate error-prone conditions or
check for them and present users with a confirmation option Consistent and intuitive mapping
Match between system and real world
before they commit to the action.
Visibility of State - An ambient display should make the
Recognition rather than recall - Minimize the user's
memory load by making objects, actions, and options visible. states of the system noticeable. The transition from one state
The user should not have to remember information from one to another should be easily perceptible.
part of the dialog to another. Instructions for use of the system Aesthetic and Pleasing design – The display should be
should be visible or easily retrievable whenever appropriate. pleasing when it is placed in the intended setting.
Flexibility and efficiency of use - Accelerators -- unseen by Useful and Relevant Information – The information should
the novice user -- may often speed up the interaction for the be useful and relevant to the user and the intended settings
Visibility of System Status
expert user such that the system can cater to both
User Control and Freedom
inexperienced and experienced users. Allow users to tailor
Easy Transition to More In-Depth Information - If the
frequent actions.
display offers multi-leveled information, the display should
Aesthetic and minimalist design - Dialogs should not
make it easy and quick for users to find out more detailed
contain information which is irrelevant or rarely needed.
Every extra unit of information in a dialog competes with the information.
“Peripherality” of Display – The display should be
relevant units of information and diminishes their relative
unobtrusive and remain so unless it requires the user's
visibility.
Help users recognize, diagnose, and recover from errors - attention. User should be able to easily monitor the display.
Error Prevention
Flexibility and Efficiency of Use
Research has shown that these revised methods of
evaluation are 9% more effective at identifying
usability problems per an evaluator. These new
heuristics have become a standard for heuristic
evaluation of ambient displays (Altosaar). Since
only the heuristics are revised, all the benefits of
heuristic evaluation are preserved and no additional
costs are incurred in this process.