Eye Tracking: Is it Really Necessary?

A Researcher’s Perspective.

I confess that every time a client asks for eye tracking as part of a user study, I ask myself, “Is it really necessary?”

To answer this, let me first say, what I love about eye tracking is that as an observer, you can literally see where people look for key information and navigation. And when you see gaze patterns repeated, you gain insights to support design decisions.

That said, does eye-tracking offer “better” or “more” insights than qualitative research without eye tracking? Our view is, no it doesn’t, not in most cases. However it does add data to support analysis, and it provides evidence to support study findings, which can be invaluable for more complex studies.

What is the extra effort and is it worth it?

There is extra effort at each part of a study when you use eyetracking – from planning, set-up and technical support, to data capture, analysis and reporting. So for small or fast turnaround studies, it’s probably not worth the effort or extra cost.

However, for large or complex studies, where there are challenging decision-making environments and/or specific interface design challenges, and/or when team members will be observing first hand alongside researchers, having objective data from eye tracking can add signifiant value overall, even though it may add 10-20% to the cost of a study.

Does Spatial recommend eye tracking?

It depends on the study. In many cases traditional methods alone provide fast and efficient feedback to guide a project in the right direction. In other cases we believe that eye tracking is invaluable for pulling together a complete picture of the user experience.

Our lab and experienced researchers support eye tracking for desktop and mobile experiences. Our view is that even if eye tracking is not relevant for every project, it should be available as a diagnostic tool, when necessarily.

A Deeper Dive into Eye-Tracking in Qualitative Research

How Eye-Tracking Technology Works

The basic aim of eye tracking is to record the eye movements of participants while they engage in looking behavior.

This is done by putting the participant into a set of eye tracking glasses or in front of a desktop eye tracker. The eye tracker emits non-visible infrared light that creates a reflection in the eye. This allows the tracking software to differentiate between the iris and the pupil and measure the movements. Once the eye tracker is correctly positioned to capture the eyes, the images are calibrated by having the user look to certain points on the screen. Doing this allows the software to confirm the relationship between the reflection pattern and the correct location on the screen.

As the user interacts with the product, the software records the location and duration of saccades (eye movement between points) and fixations (where they stop and idle). The combination of saccades and fixations generates a scan path which shows the order of where the user looked.

Getting the Full Story

Eye tracking offers extra information about how a user is approaching the product. However, the only data recorded is where the user is looking during product use and how intently. It doesn’t tell us why a user looks where they do, what they are thinking or how they feel about the experience. These questions are typically answered through user interviews or surveys that help tell the full story of an experience.

Eye Tracking in Practice

While eye tracking equipment is becoming more affordable, there is still a rather steep learning curve to understand how to use it properly and how to analyze the data. The research team needs to be knowledgeable and confident in how to apply eye-tracking, and when to advise against it.

Even though it is tempting to run eye tracking for the full duration of a user test, and collect data for every point of interaction, we suggest identifying the best use-cases based on the objectives of the study, and then setting up the tasks to enable clear data capture.

Having an impressive-looking heatmap that contains general metrics, but cannot speak to specific concerns is useless. Being strategic about eye tracking means we are only collecting data related to targeted objectives that will produce actionable data.

Also, be prepare for situations where the equipment can’t calibrate to a participant’s eyes, which can happen for a variety of reasons such as certain types of glasses, eye shape, etc. Know when to give up and move on without eye tracking.

How to Incorporate Eye Tracking into a Research Study

Bringing eye tracking into a research study takes extra effort at each part of the study:

Planning – You’ll need to identify the best use-cases and figure out how best to use it as you design the test plan and discussion guide. You’ll also need to factor in eye-tracking calibration in the timing of the session.

Set-up – You’ll need to do more test runs of your technical set up and make sure the moderators and observers understand the set-up and how to troubleshoot. You’ll need to add eye tracking data to any consent/disclaimer forms.

Testing – you need to introduce each participant to the technology so they are comfortable with it. Note that the equipment may not always work with some users, so be prepared for this.

Data capture and handling – Effectively you are capturing an additional video feed so this needs to be converted, edited and handled in conjunction with other video capture.

Analysis – Review and analysis of eye tracking findings gets factored into findings.

Reporting – Eye tracking findings get incorporated into the report.

Advanced Research in Partnership with UBC’s Brain, Attention and Reality Lab

Through our partnership with UBC’s BAR Lab, Spatial has access to eye tracking technology for VR/AR headmounted displays. Our collaboration allows us to explore advanced research methods and the human impacts of emerging technology, that benefit our clients.

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