Saul Greenberg > courses > lecture topics in HCI > design guidelines and usability heuristics

Usability Heuristics

Guidelines to design have a long tradition in interface design. There are literally thousands 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. In particular, I show how guidelines can be used as a low-cost evaluation technique via heuristic evaluation. Through this method, several evaluators inspect the interface for compliance to the guidelines. While heuristic evaluation does not require users' involvement, it still manages to capture many major usability problems.

Overheads

• Design guidelines and usability heuristics, [PDF] or [Powerpoint]

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

1. Improving a Human-Computer Dialogue, Nielsen and Molich, March 1990, Communications of the ACM 33(3), ACM Press.
2. Chapter 5: Usability heuristics. Nielsen, J. (1993) In Usability Engineering, p115-163, Academic Press.

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.

Additional Readings

1. Enhancing the explanatory power of usability heuristics. Nielsen, J. (1994) In Proceedings of the CHI'94 Conference on Human Factors in Computing Systems, p152-158.
   • This article takes usability guidelines developed by different sources and sees which ones contribute most the the explanation of actual usability problems drawn from a database.
2. Chapter 2: Heuristic evaluation. Nielsen, J. (1994) In J. Nielsen and R. Mack (eds) Usability Inspection Methods, p25-62, Wiley and Sons.
   • A more in depth discussion of how heuristic evaluation works and its reliability
3. Excerpts from Human Computer Interaction: Towards the Year 2000 by Baecker, Grudin, Buxton and Greenberg, Morgan Kaufmann Press.
   • 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

1. The Piano Tutor, by CMU (1990, SVGR 55) 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.
2. The Sonic Finder, by Bill Gaver shows how everyday sound can be used to provide feedback of user actions. 

Major sources used to prepare lecture material

1. The readings offered above offer much detail.
2. Nielsen's Usability engineering, 1993, Academic Press, details the heuristics.
3. 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.
4. 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].