Jul 12, 2010
One of the strengths of the UX industry is the diversity of the people in the field. This diversity ensures variety in the perspectives UX professionals contribute to the design of a product. Every user researcher has a unique background, and each researcher’s background results in different strengths. As founders of Metric Lab, we’ve both benefitted from having a formal education in research—in the form of Master’s degrees in experimental psychology. In the course of our work, we’ve met very few user researchers who have had the formal training in research we’ve had. We’ve met qualified and experienced researchers with backgrounds in fine art, finance, human-computer interaction, communication, political science, and many other fields. All of these researchers were able to do their jobs effectively, but our training has provided us with resources they were unable leverage in the same way. Therefore, this month, we’ll discuss some of the strengths we’ve gained from our education in two areas: research and human factors.
Formal Research Education
A formal education in research helps you to understand user research at a fundamental level. For example, research education ensures you understand the differences between:
objective and subjective data—User research data falls into one or the other of these categories. Researchers obtain objective data through direct observation or measurement of participant behavior. Subjective data, on the other hand, is data participants provide by self-report through interviews and surveys. While subjective data is easier to collect, user researchers generally consider objective data to be more reliable and accurate—mainly because of the well-documented confounds researchers often experience with subjective data, such as recall errors and biases.
single-factor and factorial designs—These are types of experimental design. Single-factor designs have a single variable that a researcher controls—the independent variable. A factorial design includes multiple independent variables and testing encompasses all combinations of the various independent variables. For example, a concept test of a new mobile device with both men and women would be an example of a single-factor design with gender as the independent variable. Adding age group as a second independent variable, then testing all combinations of age group and gender would represent a factorial design.
Single-factor designs rarely provide an adequate understanding of the real world, because they do not reflect the complexity of reality. Factorial designs, on the other hand, can quickly get out of control as you add more factors and more variants of each factor. In our example, having two genders and two age groups generates four distinct groups of people; but if there were three age groups, there would then be six distinct groups. If you introduced another independent variable such as smartphone ownership, the number of groups would increase to 12.
The complexity of factorial designs can dramatically affect recruiting, because your participants must adequately represent each distinct group. A researcher could choose not to study all possible factors when devising a factorial design. However, the researcher should then be very careful when drawing conclusions based on the research. In our example, the researcher might specify that the study’s conclusions apply only to women between the ages of 25 and 35 who do not own a smartphone rather than making general statements about women or even women who do not own a smartphone. The most useful studies tend to be factorial designs that limit the number of independent variables to a reasonable range.
between-subjects and within-subjects variables—These are both types of independent variables. Between-subjects variables are independent variables that tend to be representative of different groups and get measured only once—gender is a great example. Within-subjects variables are independent variables that differ within a group and are measured multiple times—a good example would be experience with a smartphone. You can treat within-subjects variables as between-subjects variables by separating the characteristic levels of an independent variable into distinct groups, then measuring them once. An example would be recruiting some people who have smartphone experience and some who don’t, then putting them through the same test. Researchers commonly use between-subjects designs to examine differences between groups, while they often employ within-subject designs to study how people might change over time.
Though understanding some of these aspects of research might not be that important in the typical, day-to-day work of a user researcher, when it comes to doing something a little off the beaten path, these are the sorts of things you need to know to innovate research methods, while still maintaining a solid study.
As user researchers, we work on a lot of projects that are somewhat different from the typical research project. For example, on a recent project, we did a usability study that required participants to drive a car while using a device. Our client came to us because they weren’t sure how to go about performing this kind of study. Luckily, we’ve had experience with methods of usability testing that enabled us to handle the additional challenges of performing a usability test in a moving vehicle.
For this study, safety was a major issue. We had to make sure participants could perform all necessary tasks, using the planned product when driving a vehicle on public roads, while still maintaining safety and gathering all the data we needed. To accomplish this, we worked with a licensed California driving instructor and used a dual-control vehicle. The driving instructor acted as a safety driver, monitoring the vehicle and traffic and ready to engage the secondary controls whenever necessary to avoid collisions. Additionally, we scouted and prepared a route that represented a variety of traffic conditions and identified locations that were well suited to performing specific tasks. Finally, we built specialized rigs that let us mount various pieces of audio and video recording equipment in a vehicle.
As we took all of these steps in preparation for performing a usability study in this specialized environment, we had to pay special attention to preventing potential problems that might get introduced into the study. For example, we had to ensure that the safety driver wouldn’t help a participant to complete tasks. We planned how we’d cover contingencies such as participants’ missing turns or making the wrong turns. Plus, we had to counterbalance different types of participants with different times of day to account for different traffic and ambient lighting conditions. Thanks to our understanding of research fundamentals, we were able to manage all of these factors
Having a fundamental understanding of research allows us to be flexible and innovative in meeting our clients’ user research goals and gives us the capability to answer just about any user research question. We can create custom approaches to user research—whether for innovative products or to answer unique research questions—and produce actionable data. Whether we are assessing visual scan patterns on a mobile device, observing the moment-by-moment emotional reaction of shoppers in a retail environment, or studying how people decide what they want to do in an amusement park, we can do user research that fits our clients’ specific needs.
Human Factors Education
Although the primary focus of our formal education was on research, we also learned quite a bit about human factors. Then, when performing research at NASA, we expanded on our knowledge of human factors. Human factors is a discipline that incorporates knowledge of human capabilities into the design of products. These capabilities encompass human perception of auditory levels, color, force feedback, and texture; anthropometrics and their application in ergonomics; and aspects of human cognition such as workload and memory. These are all factors that have traditionally influenced product design in subtle ways that most people never realize. For example, the lights and gauges on your car dashboard tend to be in shades of red or green—as specified by the display-lighting standards the US military has developed—because blue or white lights can interfere with the unaided ability of the human eye to see in low-light conditions.
Through its understanding of the anatomy of the human eye, human factors informs the use of color in user interface design. The eye’s retina is composed of rods, which perceive levels of light, and cones, which are sensitive to different colors of light. The cones are concentrated in an area of the retina called the fovea, which is at the center of our visual field. Our peripheral vision is handled largely by the rods. Thus, when designing a user interface, it is useful to know that peripheral vision tends not to respond very strongly to color, so it is more efficacious to maximize the use color for the focal points of a product or display.
Most industrial designers create their designs for physical devices with human anthropometrics in mind. For example, they typically design handheld devices according to the measurements of different hand sizes. There are several published sources of anthropological charts for men, women, and children. ANSUR, a 1988 anthropometric survey the US Army conducted, is one of the best sources for adult male and female physical dimensions. For people designing products for children, a survey the Highway Safety Research Institute at the University of Michigan conducted provides similar information for children.
Human factors also includes cognitive capacity, including memory, attention, and workload. By understanding memory limitations, UX designers can work to keep memory demands below tolerance thresholds by automating some tasks or providing prompts that can help users. Designers’ knowledge of focused attention guides their design of alerts and alarms that call attention to system anomalies or malfunctions. While focused attention is intense, it typically lasts no more than 8 seconds. On the other hand, designers’ understanding of sustained attention can help guide their design of deeper user engagements. Human factors recognizes that duration of sustained attention for adults has an upper limit of 20 minutes. After 20 minutes of sustained attention, people tend to divert their attention briefly before either refocusing on the original stimuli or diverting to new stimuli. By designing user experiences to conform to the limits of these 20-minute blocks, then where appropriate, providing an interaction that has the purpose of reacquiring a user’s sustained attention, a product can maintain extended spans of sustained attention.
Human factors provides an understanding of the most fundamental aspects of users’ capabilities. By understanding these fundamentals, which are rooted in human biology, you can ensure that product designs are usable and fit into users’ lives.
Education is always enriching. It increases your capabilities and improves the quality of your work. As UX professionals, it is essential that we continue to improve our educations and develop new skills. For people who do user research as a part of their jobs, we highly recommend getting formal research education. Even if it is just a single class in experimental methods, research education improves your ability to do your job effectively and gives you the flexibility to deviate from the standard kinds of studies we all tend to do on a day-to-day basis. We work in an innovative industry, so it is important for us to be able to innovate new user research methods. Having an understanding of the fundamentals of research would enable more user researchers to innovate effectively and advance the whole field of user research.
When selecting a course in research, make sure the research methods apply to fields that focus on human behavior, as opposed to other sciences like chemistry or biology. While we recognize the latter fields as the hard sciences, researchers in these fields tend to work in static, controlled environments that have little to do with understanding human behavior. Instead, look for courses in experimental psychology, human factors, or human-computer interaction, and make sure the class focuses on experimental design.
Education in human factors also provides significant value in understanding the capabilities of human beings—as dictated by human biology. Even if you can’t take courses in human factors, you can still incorporate aspects of human factors into your work by employing publicly available human factors standards documents such as MIL-STD-1472f, a great reference resource for factors like the maximum overhead lifting weight for small women and design considerations for stereoscopic (3D) displays. Another great resource that can inform your designs is ANSUR, which includes anthropometrics like fingertip size for large men, helping you decide the right button size for your next mobile application.
Education helps us all do our jobs better and make new and valuable contributions to the fields in which we work. We are always learning and adding new approaches to our repertoire of user research methods—whether it’s communication education to help us better connect with our users and colleagues or design education to better understand the needs and goals of our clients and users. If everyone in our industry were to do the same and continued to learn as much as possible—whether research methods, human factors, or anything else that would impact the quality of our work, it would help the whole industry move forward. We could develop new user research methods that would result in innovative products that transform the marketplace.