I Love Cognitive Psychology
Cognitive psychology taught me that even really smart, capable individuals are susceptible to cognitive biases simply because we’re humans and that’s what humans do. A few examples of cognitive biases are:
Confirmation Bias: Our natural tendency to be drawn to information that reinforces our own views
Hindsight Bias: A tendency to overestimate our own ability to have predicted an outcome after learning the outcome
Framing Bias: Using phrasing to affect how a decision will be made in factually equivalent situations
Cognitive Biases in Real-Life
A teacher may believe that Allie is smart. Subsequently, the teacher notices Allie always gets good grades in Math but doesn’t notice that Allie’s Math grades are average compared to her classmates (confirmation bias). In another scenario, it was really obvious that Obama won with his grassroots campaign in the last election, right (framing bias)? Everyone could have predicted that (hindsight bias).
Designers and user experience (UX) experts are also humans, so how do we present unbiased findings about your product and solutions? In user-centered design, we conduct structured usability testing to gather unbiased, objective data about the User Interface (UI) we’re building. There are many experimental design methods but today, I want to focus on eye tracking methods.
Where Are You Looking? What Are You Thinking About?
Humans are very visual creatures. The majority of our brain is allocated for visual processes and we depend hugely on our visual inputs every day. By analyzing our eye movements, we are able to gather insights about how users think and process information.
What Metrics Do Eye Tracking Machines Capture?
The quality and the reliability of the metrics you capture depends on the system and the specs of the machine. Metrics you can get from the eye tracking study include:
Fixations: A pause in eye movement. Different measurement of fixations include the number of fixations per page, the number of fixation per area of interest (AOI), or the fixation duration on a certain item or area
Gaze: The sum of all fixations for an area of interest (“dwell”, “fixation clusters”)
Saccades: A rapid eye movement between fixations. Since saccadic eye movements are very quick, to get an accurate measurement of saccades, you need an eye tracking machine with a high sampling rate
Pupil: The size of pupils change based on human emotions such as fear, anxiety, and task difficulty. With accurate measurements, pupil size can provide helpful insights into the more emotional side of user “experience”
For more information about the stories each of these metrics tell, see Poole & Ball’s comprehensive research article.
Designing an Eye Tracking Experiment
The type of usability experiment we run varies depending on the project. Some usability experiments last for weeks as we go through the system thoroughly with the users. Others may require a faster approach such as hallway testing. Similarly, eye tracking can be implemented in different ways.
Quick and Dirty Method: 5-Second Testing
If you want to conduct a quick-and-dirty lean UX study, you can incorporate eye tracking into 5-second testing. There are different methods used for 5-second tests, but generally, you show the participants the design for five seconds, remove the design, and then ask participants about the design. For example, “What do you remember about the page you just saw?” When paired with eye tracking, you can see what attracted the participant’s attention as shown in the heat map below.
When you use the average of all participants, you can quickly, and easily create a heat map for your client. Heat maps are an easy tool to visualize your results in a way that clients can easily understand.
Digging Deeper: Retrospective Think-Aloud
When you really want to dig into your users’ cognitive model of the system, just knowing what is salient to users may not be enough. To gain more insight into what users are thinking, eye tracking can be used in conjunction with retrospective think-aloud. Concurrent think aloud may disrupt user’s thought process and workflow, and it can interfere with eye tracking calibration as well. An alternative method is recording and playing back the session to the user with the recorded eye tracking visuals. Eye tracking recording helps users remember what they were looking at and you can dig deeper into why they were looking at certain information or why they missed certain information. With the added qualitative data from retrospective think aloud, your eye tracking analysis on a number of fixations, duration of gaze, etc. will help create a full story about the user’s cognitive model of the system.
Eye tracking can provide an objective, non-biased, information to UX practitioners. Appropriate usability techniques and proper analysis can lead to critical insights about user’s cognitive processes.
Want to learn more about User Experience, and how we help create better products and sites? Check out my previous blog on the important user experience questions you haven’t asked yourself.