Performance Metrics - Measuring the User Experience: Collecting, Analyzing, and Presenting Usability Metrics - page 75

“engagement” with the site, or the site is considered “stickier”. Part of the reason that
our assertion seems at odds with that perspective is that we don't agree with it. Session
and page-view duration are examples of metrics that are from the perspective of the site
owner rather than the user. We would still argue that users generally want to be spending
less time on the site, not more . But there is a way in which the two viewpoints might be
reconciled. Perhaps a goal of a site might be to get users to perform more in-depth or
complex tasks rather than just superficial ones (e.g., rebalancing their financial portfolio
instead of just checking their balances). More complex tasks will generally yield longer
times on the site and longer task times than superficial tasks.

4.2.1 Importance of Measuring Time on Task
Time on task is particularly important for products where tasks are performed
repeatedly by the user. For example, if you're designing an application for use by
customer service representatives of an airline, the time it takes to complete a phone
reservation would be an important measure of efficiency. The faster the airline
agent can complete a reservation, presumably the more calls that can be handled
and, ultimately, the more money can be saved. The more often a task is performed
by the same user, the more important efficiency becomes. One of the side benefits
of measuring time on task is that it can be relatively straightforward to calculate
cost savings due to an increase in efficiency and then derive an actual return on
investment(ROI).CalculatingROIisdiscussedinmoredetailinChapter 9.

4.2.2 How to Collect and Measure Time on Task
Time on task is simply the time elapsed between the start of a task and the end
of a task, usually expressed in minutes and seconds. Logistically, time on task
can be measured in many different ways. The moderator or note taker can use a
stopwatch or any other time-keeping device that can measure at the minute and
second levels. Using a digital watch or application on a smartphone, you could
simply record the start and end times. When video recording a usability session,
we find it's helpful to use the time-stamp feature of most recorders to display the
time and then to mark those times as the task start and stop times. If you choose to
record time on task manually, it's important to be very diligent about when to start
and stop the clock and/or record the start and stop times. It may also be helpful
to have two people record the times and to be unobtrusive in recording the times.

AUTOMATED TOOLS FOR MEASURING TIME ON TASK

A much easier and less error-prone way of recording task times is using an automated
tool. Some tools that can assist in logging of task times include the following:
• UsabilityActivityLogfromBitDebrisSolutions( http://www.bitdebris.com/

category/Usability-Activity-Log.aspx )