Among all the books that discuss about eye-tracking and user experience, our personal favourite has to be:
A Practical Guide to Research
By Aga Bojko
As you might have expected, this book will teach readers how to do eye-tracking studies the right way, choosing the right device, analysing and presenting the right way, and so on and so forth…..Yes, it virtually covers every aspect of what you need to know and consider before adding eye-tracking to your research toolkit.
Richly illustrated and clearly witten, this book stands apart from similar books in that it presents information in an approachable and accessible way. Despite all the technical bits, reading it certainly did not give us the feelings of reading a textbook!
However, the main reason why we like this book is the main theme that runs throughout the book: “Think first, Track later”. Aga Bokjo advocates that eye-tracking will not always be the most appropriate research methodology, unless the data it generates can be used to answer particular research objectives. Check out an excerpt for the book here.
By being brutally honest about the real benefits and limitations of eye-tracking, this book offers a refreshing take on the controversial research method. Coming from a background that blends rigorous academic research with an abundance of UX industry experience, Aga Bokjo gives us “actionable insights” and guidance to adopting (or not) the eye-tracking research methodology. Because of the scientific rigour that Aga Bokjo tries to instill in readers, this book appeals not only to the UX industry, but to the academic world as well.
Do you want to find out how eye tracking can help your research? Do drop by Objective Experience and pick up a copy of the book. Alternatively drop us an email at firstname.lastname@example.org for a knowledge sharing session.
Lynette Goh, our very own senior eye tracking research consultant, recently spoke at the South East Asia POP (Point of Purchase) Summit in Manila. She described how wearable eye tracking helps brands and retailers in understanding shopper dynamics and their interaction with in-store marketing.
Tobii Glasses 2 were showcased at the event and demonstrations were booked solid through out the conference.
This is the next wave of scientific research in shopper research in the Philippines, are you on board? Contact 11_FTC for consulting services in Manila.
We are proud and excited to announce that Objective Eye Tracking is collaborating with Prof. Gemma Calvert and her team of researchers at Nanyang Technological University on a grant project awarded by The Institute on Asian Consumer Insight (ACI).
This ground breaking research project will seek to understand Asian consumers’ sustainable living perceptions and how that translates into their shopping behaviors. The project tackles key strategic topics under the Possible Future Worlds research initiative at ACI. The mission for this project is to better understand how we can reduce the impact that humans have on Planet Earth.
We will probe into the consumers’ subconscious attitudes and emotions about sustainability, recycling and eco-shopping using cutting edge methods including the Implicit Reaction Time tests and Eye Tracking with the Tobii Pro Glasses 2. These methods will help us uncover new insights that are not easily accessible via regular self-report measures and derive new solutions that will help change human behavior and make a difference.
About ACI (The Institute on Asian Consumer Insight)
ACI was created to help international brands understand Asian consumers and develop business strategies to succeed in Asian markets. By applying the latest market research methods, including psychometrics, biometrics and data-driven approaches, we tap into the deep-seated cross-cultural and often subconscious influences on consumers behavior so that our clients can predict their responses across different Asian markets. ACI also conducts and sponsors research on all aspects of Asian life and disseminates many of these findings on their web-based knowledge platform, Insight+. For more details about ACI, how we can help your company to better understand your target Asian audience, or find out more about our educational programs, please visit us at ww.aci-institute.com.
ACI is a joint initiative between the Singapore Economic Development Board (EDB) and Nanyang Technological University (NTU) and is hosted at NTU.
About Objective Eye Tracking
Objective Eye Tracking are the leaders in Eye Tracking in the Asia Pacific Region. We sell and rent Tobii Eye Trackers to universities, market research agencies, corporates, UX and usability companies across South East Asia, Australia and New Zealand. We have a team of passionate Customer Experience Consultants who aim to improve the experience of a brand, across every touch point (both online and offline), and are the leaders in using eye tracking technology to uncover unconscious insights which can be used to improve the customer experience.
If you are planning to buy a eye tracker, you might have come across the varying sampling frequencies that different eye trackers are capturing gaze data at. Like Accuracy and Precision, higher sampling rate is often seen as better for data validity. However, this is not entirely the case.
Sampling frequency refers to how many times per second the eye position is measured. For example, a 120 Hz eye tracker collects 120 data points for each of the tracked eyes. In order to understand which sampling rate you need for your eye tracking study, let us first take a look at a few types of eye movements and events that are typically studied.
- Fixation lengths (or duration) typically varies from 100 – 800 milliseconds. During these fixations, the brain starts to process the visual information received from the eyes. This is the time when most information from the scene where a person is looking at is acquired. Fixation lengths usually gives an indication of information processing and cognitive activities.
- Fixation patterns can also indicate certain cognitions e.g., many short sporadic fixations can illustrate confusion, random searching or a lack of content deemed interesting or useful.
- Saccades are extremely fast movement (“jumps”) of the eyes from one fixation to
another. During a saccade, vision is largely suppressed. This is known as “saccadic
- The end point of a saccade is “decided” before it occurs and it cannot be changed in the middle of the movement.
- Saccades typically range in duration of 10-40 milliseconds, depending on the distance travelled by the saccade.
- Smooth pursuit is one of the 2 ways that visual animals can voluntarily shift their gaze, besides saccades. Smooth pursuit allows the eyes to closely follow a slowly moving target, while preserving the stability of the visual image of the target during eye movement. Any other objects beside the target are poorly processed.
- Smooth pursuit typically range from 90 – 150 milliseconds, but is largely limited to the angular velocity of the moving target. The angular velocity limit of smooth pursuit is typically ~30o/sec, and if the target is moving beyond this limit, “catch-up saccades” would occur.
- Smooth Pursuit is asymmetrical. We typically perform better when we follow objects moving horizontally, than vertically. Even for vertical pursuits, humans are typically better at downward than upward pursuit.
- Vergence occurs when both the left and right eye move in opposite directions
- Vergence can involve either a convergence (when object is getting closer) or divergence (when object is getting further) of the lines of sight of each eye.
- Vergence is the slowest speed eye movement (about 20 times slower than saccades) and are rather small in angular amplitude (typically only a few degrees for each eye)
Vestibular Ocular Reflex (VOR)
- VOR is a reflex eye movement that goes contrary to head movements, so as to keep the image of the object in fixation more or less the same place on the retina.
- VOR is one of the fastest reflexes in the human body, with eye movements lagging the head movements by less than 10 milliseconds.
With the main eye events covered, let’s go back to the sampling frequency of eye trackers.
Higher sampling frequency produces better temporal resolution (or accuracy). Lower temporal resolution would mean higher sampling errors. In fact, the average sampling error approximately equates to half the duration of time between samples.
For example, a sampling rate of 1000Hz (1 data point every millisecond) would produce an average error of approximately 0.5 milliseconds, while a sampling rate of 60Hz (1 data point every 16.67 milliseconds) would produce an average error of approximately 8.3 milliseconds. Based on the typical duration of the eye events above, an 8.3 milliseconds error might be considered too large to study saccades and VOR, but not too significant for fixations.
Be mindful that more sampling errors would lead to more “noise” in your data. There are 2 main ways to mitigate data “noise”. One is to collect more data (participants), or alternatively, you can use a higher sampling frequency for your eye tracking study.
Now let us zoom a bit into fixations. For fixations, you can be interested in where people look (fixation location), and also for how long (fixation duration). For the former, a higher sampling rate does not necessarily gives you better accuracy for identifying gaze location than a lower sampling rate. However, for the latter, a higher sampling rate can give you more precision in identifying when a fixation starts and when the fixation stops.
Given that eye tracking systems cost higher for higher sampling rates, how high do you really need to go? As you might have known, sampling errors can never be completely removed entirely, but they reach insignificance below a certain point. The level of this point depends on the type of eye events you are studying, and the research rigor in your domain of research. For example, researching saccades, VOR or other micro eye movements would require sampling rates of 250Hz and higher, but they are usually only of interest in the academic domain such as neuroscience. For vergence and smooth pursuit, a sampling rate of at least 120 Hz would be preferable.
In the UX domain, the general rule of thumb is to use sampling frequency of 60 – 120 Hz, as most of the time we are only interested in fixations, and sampling errors of around 10 milliseconds for fixation duration are still considered acceptable. If you are only interested in measuring where people are looking at, a 30Hz eye tracker would most likely suffice.
For a more in-depth discussion on eye tracking sampling frequency, watch the Tobii Pro Webninar below:
For more eye tracking essentials, visit Tobii Pro’s Learning Centre to optimize what you can do with your Tobii Pro eye tracker!
This is a list of eye trackers that Tobii Pro have to offer:
Screen-based Eye Trackers
Wearable Eye Tracker
Alternatively, you can visit Objective Eye Tracking for a comparative glance.
If you would like to know more about eye tracking and how it can help you in your research, drop us an email at email@example.com or call us at +65 67374511.
Edith Conan University in Perth is! In psychology, Dr. Shane Rogers and his honours students are using 2 pairs of Tobii Pro Glasses 2 in a unique and exciting way, to understand how two people interact with each other.
Using the eye tracking research methodology is such a novel and exciting way to conduct psychology research that the marketing department of ECU has caught on and used it to promote the psych course. Check out their awesome marketing campaign below!
Stay tuned! As Shane will be sharing his research with us as it progresses!
P.S Check out how ECU has used the Tobii Pro Glasses 2 in a previous research study investigating the similarities and differences on the Aboriginal Australians ways of seeing the world to non-Aboriginal ways.
Great news! Tobii Pro just announced 2 new features for Tobii Pro Glasses 2 software, which will help us segment data more accurately and to make analysis faster.
New Feature: Event Logging (in Tobii Pro Glasses Controller)
The Tobii Pro Glasses Controller software now comes with the function to log live events. This enables you to highlight interesting parts DURING the recording itself. These event can also be exported, together with the other data collected, into the Tobii Pro Glasses Analyzer software.
New Feature: Time of Interest Feature (in Tobii Pro Glasses Analyzer)
This latest feature of the Pro Glasses Analyzer allows you to segment data by creating custom portions of the video recording. For example, you can choose a ‘start event’ and a ‘stop event’ to get a clearly defined set of data for a particular event of interest.
Together with the event logging feature from the Pro Glasses Controller, interesting parts of the recording can be accessed quickly and easily to create Times of Interest.
Other improvements to the Tobii Pro Glasses Analyzer includes:
- New quick-access menu
- Possibility to resume Real-World Mapping by storing all queued automatic mapping tasks when closing the program
- Major performance and stability improvements for big projects, where some operations can be 10+ times quicker now
If you want to find out more Tobii Pro Glasses 2, head over to Tobii Pro’s website for more details.