Traditional Usability Test of Running System

By Jakob Nielsen, May 1995
Sidebar to article about usability testing for the design of Sun's website in 1995.

Usability laboratory, set up for traditional user testing at a computer. Note camera and one-way mirror.

This is how most usability tests are set up: the user interface that is being tested is running on a computer in the usability lab and the user sits down at the computer and starts working. Normally, we give users a series of set tasks (e.g., find information about the Spring distributed operating system project) and we certainly did so for the web studies. For this particular type of user interfaces we also found it important to let the user spend some time exploring the information space freely: we wanted to see what interface elements the users naturally found interesting without any prompting. We did keep some set tasks since we also wanted to know how usable the design was for people who needed to find specific information.

Most tests were conducted in the usability lab as shown in the photo, though we also conducted three tests in Sun offices in Europe and Asia to assess international usability. The usability lab has a large one-way mirror that allows team members in the control room to observe the test and discuss its outcome without interrupting the test user. Some times the experimenter sits in the control room but my preference is to sit with the user in the lab itself. We have two cameras in the ceiling (not shown) and one camera on a tripod. These cameras are used to record the user's reactions to the interface as well as to film the screen. We do have a scan converter that is used to record a complete screen image, but we often find that there is some extra value from having a camera pointed at the screen because it can record cases where the user points to something on the screen.

It is hard to see on this photo, but to the right of the computer is the lavaliere microphone which we ask users to wear during the test. We have found that the only way to get good sound is to use these clip-on models since table mikes capture too much noise to make it clear for people in the observation room what the user is saying.

A small trick: we have a small table clock to the left of the computer. This clock makes it easy for the experimenter to time the test and to manage the available session time much more unobtrusively than when having to look at a wristwatch.

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