By Shanshan Ma
As companies progressively introduce more advanced technology in their consumer electronics products, handheld devices—including smartphones, digital cameras, mp3 players, eReaders, and GPS (Global Positioning Systems)—are taking up more and more of people’s time in their everyday lives. Are users interacting with handheld devices in the same way they interact with Web sites? What kinds of challenges are users facing when using such a wide range of handheld devices on a day-to-day basis? What should usability professionals take into consideration when studying usability for these different platforms?
One Hand or Two hands?
The first big question to ask is, do users need one hand or two hands to operate a device? Interacting with Web sites normally requires the use of two hands when typing on a standard keyboard and one hand when using a mouse or other pointing device. With the vast diversity of handheld devices, users often need to make a decision whether to use a particular device with both hands or only one hand. Such a decision is sometimes contextually constrained. For example, people driving a vehicle have only one hand free when operating a GPS device. Sometimes this decision is culturally constrained. For example, smartphone users in Japan are accustomed to using smartphones with one hand, because they’re often using their other hand to hold onto a handrail on a running train. Whether a device is intended for one-hand or two-hand use can greatly impact how the device is designed and, therefore, affect how people perceive its usability. Usability professionals should take this factor into consideration when planning test tasks and creating test scenarios.
A Standard Keyboard or Different Button Sets?
When interacting with Web sites, a standard QWERTY keyboard provides a consistent working environment with which users are familiar. However, when interacting with handheld devices, users may need to operate a particular devide either by using hard controls such as buttons or manipulating controls directly on a touch screen. Handheld devices come in many different shapes, with many different types of controls. For example, the Sony Reader and Amazon Kindle 2 have very different button sets. The Sony Reader features 10 number buttons, a five-way control, a home button, a back button, a read button, and a zoom button. The Kindle 2 has a QWERTY keyboard, previous and next page buttons, a five-way control, a menu button, a home button, and a back button. Although these companies designed both devices to provide a better reading experience for users, their designers certainly have different ideas of how users interact with a digital reading device. Five-way controls make it easy to navigate up, down, left, and right. A QWERTY keypad makes it easier to type.
Lack of standardization adds to the frustration users might experience when interacting with such devices. Because of this lack of standardization, usability professionals must think of usability for handheld devices systematically instead of just focusing on single buttons. Questions such as Do users understand how to use this button? might be informative. However, it could be more beneficial to ask whether a device’s whole button set facilitates the tasks users most frequently carry out with the device and whether users can successfully find their way around or get lost in the set of buttons.
What’s a Device’s Context of Use?
Users don’t use handheld devices within a vacuum. They’re driving a car and using a GPS. Or they’re riding a train and text messaging a friend. Or they’re on a trip and using a camera to capture the view. Or maybe they’re riding a bus and reading a book on a Kindle. Everything happening around a user coalesces to create an important part of the user’s experience with the device. The context, or the environment, in which people use handheld devices varies considerably and matters greatly in evaluating the usability of those devices.
When users interact with a digital camera, they are usually trying to catch a good shot—perhaps a fleeting moment—and have very little time to operate the camera. How well designers can optimize the design of the camera, ensuring users can easily push the right buttons without making mistakes, is a very important aspect of camera usability. When users are operating a GPS, driving is usually the highest priority task. The limited amount of attention users can give to a GPS requires that the buttons in its user interface be big enough to use easily within the context of driving. This is also why voice commands are now integral parts of navigation system user interfaces.
Methods for Studying Handheld-Device Usability
With these thoughts in mind, it’s clear that usability testing in a lab might not be optimal for studying handheld-device usability. When there is a designated lab testing environment participants must go to, they enter a testing mode from the moment they step into the lab. They start thinking about the testing facility, what’s going to happen in it, and what kinds of things they might experience during the test. I have heard participants make comments like “This is new…” or “I’ve never done this before…” when entering the lab. As soon as they step out of the lab, they again become their normal selves—and perhaps start to use their handheld devices in a completely different way from what they just told us they usually do.
Even if participants are completely at ease during testing and the user researcher created a perfect test scenario, lab testing just cannot afford the type of richness a real-life setting can offer. The cultural and environmental elements of real life are absent. It’s impossible to reproduce all of the ephemeral happenings of real life that affect the way people use handheld devices in their natural environments in a lab environment.
Ideally, it would be great if a researcher could be an invisible shadow, following users around without intruding on their reality. For instance, when a user is struggling to use a new GPS system while driving, the researcher could be sitting next to him and observe every problem the user experiences. There are a couple of methods that let user researchers and usability professionals get closer to users without intruding.
In-home or at-work visits are often superior to usability testing in a lab. When researchers go to places with which users are very familiar, this allows the users to be more conformable while demonstrating their typical daily usage of a device. A conversation between a user and a researcher that occurs in a comfortable, normal environment might help users to remember certain stories about using a device that prove to be very valuable and offer opportunities for great insights.
Short-term longitudinal studies can also be very beneficial for studying handheld-device usability. Longer periods of observation let users experience the device in a more relaxed and natural way, allowing more random accidents and issues to arise. Diary studies can also be effective if users are sufficiently motivated to keep track of what happens during the course of each day throughout the longitudinal study. However, the retrospective nature of diary studies might not work for all users. Some people find it difficult to sit down at the end of a day and think about what happened during the day. An on-device diary might be a good alternative. A diary on the actual device could prompt users to enter short logs whenever there is a need.
In Summary
Users confront different usability challenges on handheld devices than when interacting with a Web site. As usability professionals, we need to consider whether a device is intended for one-hand or two-hand use. When observing users interact with handheld devices, it is more beneficial to think about a device’s usability systematically instead of focusing on the use of single buttons. Since context plays such an important role in the use of handheld devices, in-home or at-work studies, short-term longitudinal studies, and diary studies are more suitable than conducting traditional usability testing in labs.
