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5.3. USER INTERFACE SPECIFICATION

The user interface specification provides the details of the user interface for the software developers to implement. In the framework for information systems architecture (Sowa and Zachman, 1992), the user interface specification would be part of the technology model. The user interface specification expresses the technology model from the user’s view (called the Human/Technology Interface in Sowa and Zachman, 1992). A user interface specification contains all the screens for all the tasks except for error conditions and help, which are standardized in the application style guide.

The user interface specification is geared toward the software engineers who will be building the application and those who will work on fixing usability problems or extending the functionality of the redesigned application after initial roll-out. The user interface specification is also important for the quality assurance specialists who will be checking the software for conformance to the user interface specifications. Software engineers working in testing often find the user interface specification useful for developing test cases.

In fire prevention assignments, the user interface specification is prepared during the detailed user interface design phase. In firefighting assignments, there is usually no time to prepare the user interface specification or it must be reduced to a sample specification. It has been the author’s experience that, when usability resources are scarce in a firefighting assignment, time is best spent working with the software developers to review screens they have developed and coach and advise them on good user interface design rather than write user interface specifications.

6. CONCLUSIONS

It is appropriate to recognize that, regardless of the methods and techniques employed, the success of a usability engineering program depends to a large extent on the willingness of developers and senior management to accept and implement usability recommendations. Usability engineering is more often than not about making or recommending trade-off decisions between development, usability, and project issues. These decisions are business decisions (though they at first appear to be usability decisions). Usability engineers are not usually the final decision makers for high-profile issues, but can provide the information necessary for making informed choices. The recommended approach is to build a business case which supports the argument in favor of usability. A solid business case will often demonstrate the value of usability efforts to project managers and senior management, opening the door for the effective employment of usability engineering methods and techniques.

7. ACKNOWLEDGMENTS

The author would like to thank Diane McKerlie of DMA Consulting Inc. for her excellent contribution to this chapter both as a reviewer and fellow firefighter. Many of the ideas and methods presented in this chapter have been fine tuned in consulting assignments we worked on together. Her support, her sense of humor and the chocolate cookies she brings when the going gets tough are much appreciated. The author would like to thank the reviewers — Tom Graefe, Kevin Simpson, Ron Zeno, and Tom Dayton — for their detailed comments and thoughtful observations. They contributed much to clarifying the descriptions of methods and heuristics. The author would like to thank Marie-Louise Liebe-Harkort for her careful editing and encouragement. Finally, the author would like to thank Larry Wood, Ron Zeno, and the workshop participants for the opportunity to compare ideas and experiences and learn from each other at the workshop.

8. REFERENCES

Carroll, J. M., Mack, R. L., and Kellogg, W. A., Interface metaphors and user interface design, in Handbook of Human-Computer Interaction, Helander, M., Ed., North Holland, Amsterdam,1988.

Jacobson, I., Ericsson, M., and Jacobson, A., The Object Advantage, Addison-Wesley, New York, 1994.

Molich, R. and Nielsen, J., Improving a human-computer dialogue, Communications of the ACM, 33(3), 338-348, 1990.

Monk, A., Wright, P., Haber, J., and Davenport, L., Improving Your Human-Computer Interface: A Practical Technique, Prentice Hall, New York, 1993.

Nielsen, J., Usability engineering at a discount, in Designing and Using Human-Computer Interfaces and Knowledge Based Systems, Salvendy, G. and Smith, M. J., Eds., Elsevier, Amsterdam, 1989.

Nielsen, J., Finding usability problems through heuristic evaluation, in Human Factors in Computing Systems, Proceedings CHI, 1992, Baversfield, P., Bennett, J., and Lynch, G., Eds., ACM Press, New York, 1992.

Norman, D. A., Cognitive engineering, in User-Centered System Design, Norman, D. A. and Draper, S., Eds., Lawrence Erlbaum Associates, Hillsdale, NJ, 1986.

Paulk, M. C., Curtis, B., Chrissis, M. B., and Weber, C. V., Capability maturity model version 1.1, in IEEE Software, July 1993, 18-27, 1993.

Preece, J., Rogers, Y., Sharp, H., Benyon, D., Holland, S., and Carey, T,. Human-Computer Interaction, Addison-Wesley, Reading, MA, 1994.

Sowa, J. F. and Zachman, J. A., Extending and formalizing the framework for information systems architecture, IBM Systems Journal, 31(3), 1992.


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