by Janice (Ginny) Redish, Redish & Associates, Inc.
In the early days of usability testing, most design teams waited until the end of production to test. They were doing what they thought of as "validation." They hoped users would sail through the tasks and their design would emerge as a resounding success. Designers equated success in the usability test with success in the design.
If you wait until the end to do usability testing, however, you are almost certain to find serious problems in the product. And then you have the frustration of neither time nor resources to fix the problems.
This type of end-of-process, validation testing (also known as "summative" testing) has a legitimate place in the usability specialist's toolkit. However, it should not be the only usability testing that you do. Why not? Because to complete the design process with a design free of problems, you have to find – and fix – the problems during the process. Testing while the product is being planned, designed, and developed is called "formative" testing.
Instead of thinking of success as a perfect design, you should think of success in a usability test as learning what you need to know. The goal of formative, diagnostic testing is to find the critical problems that prevent users from completing their tasks.
Timing is critical. You want to learn about your design’s problems during the usability test, not when it fails after it is released. It's that eventual failure that you are working to avoid. Formative usability testing is the way to achieve success by finding and fixing problems early.
No. Success in usability testing is learning what you need to know. That includes finding out both what is working well and what is not working well.
It's important to record the positives as well as the problems – and to tell those who haven't seen the usability test about both. And that brings us to another important aspect of successful usability testing: communicating the results in a way that makes the design's team members – the managers, designers, developers, writers, and other contributors – eager to help fix the problems.
If the team members don't understand what happened in the test and how it should affect the outcome of the design, they won't make the necessary changes or will possibly change the wrong thing. A successful usability test results in design improvements.
Focusing on formative tests–with an eye toward identifying problems and bringing the issues to the team–is the secret to successful usability testing.
Are you interested in learning more about usability testing? At the Know Your Users Roadshow, Ginny Redish will teach her full-day seminar Honing Your Usability Testing Skills. In this seminar, you'll work on all the aspects of usability test planning, facilitating, note-taking, analyzing, and communicating results.