Because modern eye trackers vary greatly in performance and capabilities, the first question researchers tend to ask me is, “How much do your eye trackers cost?” And I get it, the budget for hardware needs to be spent wisely, but I don't believe that cost is the best starting point when choosing an eye tracker. In the long term, investing in a non-optimal (too high-end or too low-end) solution could cost you more in wasted time, resources, and grant funding.
In this post, I will take you through the top four criteria to consider when looking for an eye tracker for research — to help you choose the best one from the get-go.
If you’d like a copy of my in-depth report, fill out the form at the bottom of this post, and we’ll send it to you.
1. What types of stimuli do you want to show?
Do you want to present stimuli on a screen, from a real-life scenario, or both? Wearable eye trackers are great for both scenarios and ideal for observing behavior while participants are on the move. And, as their name suggests, screen-based trackers are designed for testing while participants sit relatively still in front of a computer screen.
2. What kind of participants are you testing?
Your choice of the right eye tracker may be swayed by the test group you’re planning to study. This factor is important if your population includes members of special groups, like infants, aging adults, people with medical disorders, or nonhuman primates.
In such cases, the best eye tracker might be ones that deliver wide freedom of head movement and large track-box size, for example. Solutions that don’t force test subjects to sit still or put their head in a chin rest (or require another kind of restraint) will help study participants to act and react intuitively.
3. What kind of testing environment will you be in?
Will you use your eye tracker in a traditional laboratory or in the field, such as a school classroom, hospital, or elsewhere?
For example, if you intend to travel a lot, you may need a portable solution that you can carry easily. If you are testing primarily in a lab or fixed location, a standalone system that can support real-life and screen-based stimuli may be the best option.
4. What metrics are the most important to measure your construct of interest?
In my experience, the most wanted eye movements and measurements are fixations, saccades, smooth pursuit, and pupil dilation.
These metrics often require specific sampling rate frequencies or, to put it another way, the number of data points you get per second. So the frequency of your eye tracker comes into play here.
If you were to choose a Tobii eye tracker
The sampling frequencies of Tobii eye trackers range from 30 to 1,200 Hz, and if data accuracy is your primary driving force, I’d say that’s the best place to start your choice.
Tobii Pro Fusion, for example, is a good mid-range portable screen-based solution for the lab and the field and can operate at frequencies ranging from 30 Hz up to 250 Hz. Tobii Pro Spark (60 Hz) is our entry-level solution. And if you are looking for a high-end lab solution, we would probably recommend Tobii Pro Spectrum, which supports screen-based and real-life stimuli from 60 Hz up to 1,200 Hz. If you need to record what your participants see as well as extract their eye movements, then our wearable Tobii Pro Glasses might be your best option.
In case you are working with VR in your research, our advanced eye tracking and analysis solution, Tobii Ocumen, is supported by several commercially available VR headsets that include our eye tracking technology.
Whichever eye tracker suits you best, you can be sure the data we deliver is robust — accurate, and repeatable — for all your study participants.
And you can find out more in the downloadable report by filling out the form below.