Topic: test plans

As much as we'd like to grab a few people off the street, sit them in front of our work, and shove a microphone into their faces, usability testing requires a little more planning. The purpose of the test plan document is to lay out the approach for a usability test. Test plans help set expectations for the kinds of feedback the design team will receive and help everyone agree on the aspects of the design that need testing. The test plan also prepares the team member who will be conducting the test, establishing a direction for his or her conversations with end users.


Everyone on the team benefits from usability test plans. The person conducting the test gets the most benefit by far because the test plan will direct conversations with end users in a meaningful way. Even if you're not conducting the test yourself, your involvement in preparing the test plan will ensure that your concerns will be addressed during testing.


The usability test plan is one of those documents that always takes longer than anticipated to prepare. You can put a simple one together in a couple of hours, but feedback from the team will inevitably identify additional concerns—everything from logistical problems to additional questions for users. Because usability testing directly involves customers, stakeholders usually want to get involved, which can extend the timeline for putting a plan together.


The real question here is when to do usability testing, and that can vary depending on your methodology. Most people save usability testing for the end of the project, or do it at strategic points throughout the design process. The bottom line: Whenever you schedule usability testing, you must allocate some time to put a plan together. Keep in mind that the organizational roadblocks to planning a test are significantly lower than those for conducting a test—the prospect of talking to customers can give some stakeholders cold feet—so it might be weeks or months between the planning and the doing.]


For better or worse, the usability test plan hasn't evolved much in the last 10 years. Unless you're working with a particularly innovative team, you'll find that usability test plans are straight prose documents, usually prepared in a word processor.

Though planning a usability test is fraught with challenges—logistical decisions, keeping the scope of the test in check, varying the script for different user groups—the main challenge with the test plan itself is creating a multipurpose document. This document will be used for discussing the plan with stakeholders and team members, and for conducting the actual test.

Perhaps the easiest way around this challenge is to prepare two separate documents—the test plan and the test script. Preparing two documents, however, comes with its own set of risks. Two documents means related content in two different places and two version histories to track. Perhaps these are trivial issues for you. Over the years, however, I've found it easier just to combine the documents.