Design Guidelines and Usability Heuristics
Guidelines to design have a long tradition in HCI. There are literally
thousands of guidelines now available, in many forms and variations. These
tend to fall in the categories of: motherhoods (or general guidelines);
specific guidelines that say exactly what should be done in a given situation;
style guides that are particular to a look and feel; and widget-level guidelines
that are embedded within the actual toolkit.
Most of this module develops general design guidelines, detailing what
they mean and how the interface should cater to them. I also show how guidelines
can be used as a low-cost evaluation technique via "usability heuristics".
Through this method, several evaluators use the guidelines as a way to
structure their analysis of the interface. While it does not require users'
involvement, it still manages to capture many major usability problems.
Design guidelines and usability heuristics, [PDF]
Using heuristics to explain usability problems
Widget level guidelines
Simple and natural dialogue
Speak the users' language
Minimize user memory load
Provide clearly marked exits
Deal with errors in positive and helpful manner
Provide help and documentation
Nielsen and Molich Improving a Human-Computer Dialogue, March 1990,
Communications of the ACM 33(3), ACM Press.
Nielsen, J. (1993) Chapter 5: Usability heuristics. In Usability Engineering,
Readings from Baecker Grudin Buxton and Greenberg
Chapter 2 excerpt: Heuristic evaluation, p. 82-84, summarizes the
guidelines and heuristic evaluation.
Chapter 10 excerpt: Designing to fit human capabilities, p. 667-673,
has a section on human error and a section on training, documentation,
Human error and the design of computer systems / Human error and the
search for blame, p. 681-685, is background for the Dealing with Errors
guideline. The two papers talks about human error and why design should
account for it.
Designing for error, p686-697, is also background for the Dealing
with Errors guideline. Gives specific recommendations of how design should
deal with human error.
Learning to use a word processor, p. 698-717, is background for
the Provide Help guideline. The article talks about how people learn to
use software, and lays the background to minimalist manuals (as discussed
in the Chapter 10 introduction)
Building user-centered on-line help, p. 718-723, is background for
the Provide Help guideline. The article talks about how to build on-line
Consistency, various excerpts, p. 59-61, 66, 426-27, 434, gives
examples related to the consistency guideline.
Feedback, excerpt, p. 18 gives examples related to the feedback
Usability inspection methods, p. 170-181, gives a summary of a variety
of ways to inspect interfaces without the user, including heuristic evaluation.
It also discusses their effectiveness.
The Piano Tutor presents a piano tutoring tool that
is in the language of the user ie, input devices are the piano (mostly),
and output is via score annotation, music playing, and video lessons. It
also demonstrates how error correction is done, and how help is provided
in context. The Sonic Finder shows how everyday sound can be used
to provide feedback of user actions.
The Piano Tutor, by CMU (1990, SVGR 55)
The Sonic Finder, by Bill Gaver
In-Class Teaching tips
With each guideline, I do a heuristic evaluation of two interfaces
in class. The interfaces are Cheap Shop (already used in the task
centered system design section), and Mantel (see the Nielson and Molich
source below). The students analyze the interface in class and come up
with potential problems.
There is also a hands on component. If students do final projects, they
are evaluated via the heuristic evaluation method. Students get a check-sheet
ahead of time with the guidelines written on it. I schedule a half-hour
with each project group, and do a heuristic evaluation of their system,
discussing the results with them.
Major sources used to prepare lecture material
The readings offered above offer much detail.
Nielsen's Usability engineering, 1993, Academic Press, details the
Nielsen, J. (1994) Chapter 2: Heuristic evaluation. In J. Nielsen and R.
Mack (eds) Usability Inspection Methods, p25-62, Wiley and Sons
details when, where and how heuristic evaluation are effective.
Specific interface guidelines for text-based transaction systems are offered
by Smith and Mosier's Guidelines for Designing User Interface Software,
MITRE Corporation [Ftp