During my 20 years as a usability consultant with IBM, it was the rare corporate client that was willing to pay for extensive usability testing. Many clients expected that since we were “user interface experts” we would be able to design a great and usable interface in short order. To cope with the resulting time pressure, we developed several methods for rapidly iterating and evaluating user interface designs. Even so, there remained the question: when do you stop iterating? In other words, when is a user interface good enough?
Report Abstract
When is the usability of a new user interface design good enough to stop trying to improve it? To answer this question, we propose that usability ratings should be scaled in terms of specific usability criteria, and we evaluated this proposal in an iterative user interface design effort. We also tested our hypothesis that usability ratings arise from the interaction of three user interface dimensions: content, functionality, and layout. We found that scaling usability ratings in terms of specific requirements was effective in identifying when to stop iterating a design, and that ratings of the UI dimensions predicted the usability ratings.
Citation
Fracker, M. L., Heck, M. & Goeschel, G. (2010). When a user interface is good enough: User ratings in UI design. Proceedings of the Human Factors and Ergonomics Society Annual Meeting, 54(6), 595-599.
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Dr Martin Fracker 