Usability lab

In a controlled environment, a number of observers watch the way in which one or more users use the system. Besides usability experts, it is advisable to invite a number of designers for this. A few tasks are selected for the user to perform that are typical taks to be performed with the application.

A task description typically consists of:

  1. A sketch of the starting point, consisting of a description of the role that the subject assumes and their background, e.g. an inexperienced user or an experienced administrator
  2. One or more tasks, e.g. check the status of the last order, compare the prices between two suppliers and order an item from the cheaper of the two. The task should indicate what has to happen, but not how the user should do it.

The subjects should read the role description and prepare themselves to carry out the tasks from that background.

During the execution of the tasks, the idea is that the subject continually thinks aloud and says what he or she is doing. For example, a reaction can be “I’m now going to the menu and opening the option of ‘Information on company X’, to see if I can find the route map there. Oh no, it’s not here… (Etc.)”.

The onlookers observe the behaviour of the user and take notes. In a so-called usability lab, the observers remain behind a one-way mirror and everything is recorded on video (both the images of the user and the images and operations on the computer). Another technique, such as eye tracking (the registering of eye movements on the screen) and other physiological measurements (heartbeat, perspiration) are possible here. Because of the infrastructure and equipment used, a usability lab is generally (very) expensive. A cheaper, but less effective, alternative to a usability lab is to have the observer sit with the user and, for example, just use a video camera or use a tool to register the user’s actions on the system. The observer(s) then assess the usability of the system on the basis of e.g. the number of mistakes made, the time taken to complete a task and the navigation path followed. They also use the participants’ remarks during the test in their assessment of the usability.