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ISSUE 02 - Q2 2002

The Bottom-line of Prototyping and Usability Testing
- How user-centred design techniques can make a cost effective workflow

Critical parts of user-centred design, such as prototyping and usability testing, are often considered flights of fancy which only increase the cost of a Web project. But these design methods actually have their legitimacy in cost effective development. Though they add a few percent to the development expenses up-front, they can reduce the cost of making changes due to unanticipated client and user requirements by 10 to 100 times.

The Reality of Web Projects

The majority of Web projects employ what we could call a no-nonsense approach to product development, where none but the most obvious steps from idea to the finished product are taken.

This is a common way to organize Web projects:

 
"The main reason why user-centred design techniques aren't used in practice is that they are believed to be uneconomical, time consuming and altogether a luxury, which can be done without."

 

 

 

It goes like this:

  1. Requirement specification: The customer's requirements are documented in a requirement specification (if not approved by the client, repeat this step)
  2. Graphic Design: The graphic design is done (if not approved by the client, repeat this step)
  3. Web Design: The graphic design is implemented in HTML (if not approved by the client, repeat this step)
  4. Programming: The Web design is handed over to the programmers who cobble it together with the back-end (if not approved by the client, repeat this step)
  5. Launch

This workflow is almost identical to the classic waterfall model, which has been heavily criticized for its rigid sequential process, where everything is based on a requirement specification, and each stage is signed off by the client without testing if the system actually meets the requirements of the end users. Many projects have failed big time using this framework.

A Worst Case Scenario

If you've been involved in the Web business you have probably experienced situations as these:

  • A client hires a Web agency to design a new Internet solution
  • The client and a consultant from the agency specify the formal requirements in a requirement specification
  • The agency starts developing
  • As the product takes form, several misconceptions and shortcomings are uncovered
  • The problems are corrected by stopgap solutions, because there is no budget for unforeseen changes
  • The design suffers by ill-considered concepts and stopgap solutions, but the client decides to launch it anyway because of pressure from his organisation
  • After numerous complaints from users and from within the client's organisation, the client decides to have another agency re-design the whole thing

This is of course a worst-case scenario. But I'm sure that most people involved in Web development - and traditional software development - have experienced some of these frustrating incidents to the waterfall model.

The drawbacks of the Waterfall Model

The waterfall model is a very alluring approach because it takes the beeline between specification and launch. But as the example illustrates, there are two major drawbacks to this way of organizing Web projects:

  • Changes during product development are inevitable, costly, time consuming and a source of disagreement between the Web agency and the client
  • Usability problems aren't revealed until after product release, when changes are very costly

But experience has proven that these negative aspects can be overcome by:

  • Using prototyping to avoid major changes during product development
  • Applying usability testing to anticipate unforeseen user requirements

With prototyping and usability testing, we can improve the cost efficiency of the development workflow, by allowing client and user representatives to be involved in the process, discover interface problems at an early stage, and thus avoid major overheads on reworks down the line. This up-front investment will pay off in the long run. In the world of software design, it's a common lesson that the costs of changes grow exponentially throughout the development process. It's a rule of thumb that the cost of fixing a problem is 10 times higher during product development, than in the period of prototyping, and 100 times as high after product release.

The value of prototyping

Prototyping can save you both time and money because it's a fast and inexpensive way to concretise, what a requirement specification fails to do. Since prototypes can visualize the product's workings to the client, you can deal with the shortcomings, misconceptions and disagreements that tend to appear as the product takes form.

The full benefits of prototyping is multiple:

  • Prototypes comply with the wish to show fast results to the client
  • Prototyping legalizes experimentation and many revisions because it's inexpensive to alter
  • Prototypes are easy to grasp because they simulate how the final product will work
  • They can work as a common reference, and bring a disparate team together
  • Users, developers and the clients will focus on content, structure and functionality, and will not be distracted by the details of graphic design
  • Prototypes make it possible to get a formal approval of the design from both programmers and the client before you proceed to the development stage
  • They make it possible to start usability testing at an early stage in the development process

The value of usability tests

Though the odds of making a usable product are better when doing prototyping, there's no guarantee if users aren't involved in the process. Everyone implicated in the creation of a prototype will suffer from the disease of familiarity, and everybody - including the interaction designer - can come up with fixed ideas that will mess up the user experience. And you can't rely on presumptions and opinions on what the users might prefer - you have to study their actual behaviour.

The major benefits of usability testing:

  • Usability tests can help you understand how real users will use your product, and how the interface could be improved accordingly
  • Usability problems identified at an early stage can be solved easily and quickly, compared with problems identified after launch
  • Usability tests can stop endless discussions about what we think the users might prefer
  • Usability testing can be used to identify unnecessary features which can be eliminated

Unfortunately, usability testing is often done in late hours, when only minor adjustments are possible within the budget and time scale. Using cheap, small usability tests during prototyping can speed up the process, and help you focus on the issues that matter to the users.

Make it easy

The main reason why user-centred design techniques aren't used in practice is that they are believed to be uneconomical, time consuming and altogether a luxury, which can be done without. But sticking to the waterfall model is like peeing in your pants. It will get back at you with expensive changes during development and major costs on re-engineering the product after launching.

Applying user-centred techniques such as prototyping and user testing does add a few percent to the budget up-front, but can reduce the overall costs significantly in the long term. And the finished product will be markedly more usable, making it a better experience for the customers to do business with the company.

Text: Henrik Olsen

   

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