Beyond the Usability Lab

6.1.2. Task times

As described in Chapter 2, sometimes how quickly users can get their tasks done is just as important as their task success. In fact, sometimes the two measures go hand in hand. Consider the case of a portable automated external defibrillator, which is used to administer shock to a victim of sudden cardiac arrest. To be most effective, the first shock should be delivered within 3–5 minutes of the cardiac arrest. The appropriate measure of task success is actually a combination of delivering the shock correctly (e.g., with the electrodes placed properly) and within a certain period of time. Although most of us don't deal with design for these kinds of life-and-death situations, we do often deal with cases where time is important ...