The Joys of Prototyping

By creating and testing interfaces in rough format, designers are able to feed through improvements and feedback from users quickly and easily. This in turn helps to ensure a final product that is an evolved solution.

At the heart of any good user-centred design process is the practice of prototyping. By creating and testing interfaces in rough format, designers are able to feed through improvements and feedback from users quickly and easily. This in turn helps to ensure a final product that is an evolved solution, in the sense that it has been through a number of iterations and emerged as fit for the job in question.

Obviously prototyping saves time and money. If designers insisted on testing each new development on a fully-featured site only, iterative design would be a long and costly process. Rough prototyping, with pen and paper, Visio, or any other method, is both faster and more convenient. Changes can even be made while the user waits.

Convenience is a strong enough argument, but there is also convincing evidence that rough prototyping is superior in terms of the final result for a number of reasons, including:

• Users are more forthright in criticising 'unfinished' interfaces. No matter how much they may be encouraged to do so, some people are reluctant to find fault in work that appears to be set in stone. They may feel that they will be regarded as difficult for example. Although still present, this effect is noticeably reduced when users are asked to comment on work that will clearly need further work anyway.
• Interaction designers are likely to be more creative in terms of problem solving if changes can be made quickly and if necessary 'on the fly'. Experimental approaches can be tested quickly without extensive effort, meaning a greater range of possible solutions will tend to be put before the user.
• Prototyping enables the designer to concentrate on those areas of most importance to the interaction process. For example, 'vertical prototyping' will focus on deep interaction, for example when the user moves through a number of screens in order to complete a task. Horizontal prototyping, on the other hand, will examine the user's experience of a single screen in order to assist in decision making, for example. In this way prototyping can effect rapid change whilst leaving other things equal.

As the prototyping stage comes to a close, designs will begin to be firmed up. Ideas can be more fully implemented and the fidelity of the proto type increased - on the assumption that future changes will be less significant. In this way the prototyping process can lead seamlessly into graphic design work to be undertaken on an interface.

Although prototyping is most frequently used in order to help with initial interaction design, these methods can be used with great effect elsewhere in the user-centred design process. For example, after user testing, prototyping may be used to work on fixes for any problems that are identified with the finished product.