Lecture Topics in HCI, by Saul Greenberg
Contents for:	All Topics	CPSC 481	SENG 609.05	Industrial Course

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.

Overheads

• Design guidelines and usability heuristics [PowerPoint] [html]

Handouts

• Exercise: Applying Heuristic Evaluation to a Paper Prototype

Topics

• Heuristics as guideline
  1. Simple and natural dialogue
  2. Speak the users' language
  3. Minimize user memory load
  4. Be consistent
  5. Provide feedback
  6. Provide clearly marked exits
  7. Provide shortcuts
  8. Deal with errors in positive and helpful manner
  9. Provide help and documentation
• Using heuristics to explain usability problems
• Style guides
• Widget level guidelines

Required Readings

• Nielsen, J. (1993) Chapter 5: Usability heuristics. In Usability Engineering, p115-163, Academic Press.

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, and help.
• 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 help.
• 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 guideline.
• 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.

Videos

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 heuristics.
• 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, 1986 MITRE Corporation [Ftp site].