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5.2.3. The Right Tools for the Job: Using Converging Operations

Design of a system seems to require knowledge of all the system elements in order to begin the design, otherwise how can you correctly design any one element? Part of the answer to this dilemma lies in using multiple approaches to refine a design. Using iterative design with a variety of techniques puts special demands on the design process, and the next principles help guide the operations.

1.  Use the strengths of different approximations of the representing world — Pick tools (e.g., low-fidelity prototypes) so that early work is mutable at low cost, and expect it to change. Use techniques such as storyboard walkthroughs to validate broad issues of organization and modeling, because they are capable of representing whole subflows of a user interface at one time. Later in the process focus on high-fidelity prototypes to look at detailed issues in user interface structure.
2.  Infuse the represented world into the entire design and development cycle — In moving from one representation to another, and from one step in the process to the next, it is helpful to have some thread of the represented world that links design artifacts and process steps. The end user via either actual involvement or extension is key. In this project, scenarios were used to generate content at all steps, and approximations of the representing world were tested with end users at each step. In the larger system context, this point was discussed previously with regard to object-oriented design and the reuse of use cases for analyzing event flows within a software system, as well as for testing. Here the use case is the unit of value and the context of application execution.

6. CONCLUSION

This chapter has reviewed one example of how the gap between user-centered analysis and concrete design can be bridged. Essentially, it suggested in both broad process terms, and in detailed data analysis, that the gap is bridged by transforming alternative representations for the end user’s world within a representational system. The process for creating this representational system can be facilitated by systematically creating mediating representations that reveal and link the represented world and the representing world. Placing the user at the heart of the process corrects for inherent biases in the designer as they go about the cognitive task of deciding what aspects of the represented world to model and how to model them in the representing world. In this way the magic of design is grounded in knowledge of the world and repeatedly tested with the people from whom that knowledge was derived.

7. ACKNOWLEDGMENTS

I would like to thank Betsy Comstock, Peter Nilsson, Kevin Simpson, Colin Smith, Dennis Wixon, and Larry Wood for comments on this chapter.

8. REFERENCES

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