Eye Tracking Terms to Know, Part One
Eye-tracking technology has many applications across a wide range of industries and specialties, and with Gazepoint’s affordable hardware and software packages, more organizations have access to this technology than ever before. However easy we have made it to access and use this innovation, there is still much to be learned when it comes to understanding the data output of your device. In this two-part series, we’ll be discussing some of the most common terms in eye-tracking research and explaining their purpose. Read on to learn more, and order your eye tracker from Gazepoint today!
One of the most fundamental metrics gathered by eye-tracking technology is the gaze point. The gaze point represents one sample of data collected by a tracker, similar to a frame of video or a pixel in your computer screen. It records a user’s gaze with x-y coordinates and a timestamp, so you know where the participant was looking and when in a specific moment in time. The frequency with which an eye tracker records this data is represented in Hertz — 300 Hz eye-tracking hardware, for example, can record a gaze point every three milliseconds to give you detailed and accurate information.
A fixation, in the world of visual tracking, is a gaze point maintained in one place for a certain amount of time. It adds another metric to the gaze point — not only do you have the x-y coordinates, you also have the duration in time corresponding to those coordinates.
A fixation occurs when the participant stops scanning an image or page and holds their gaze in place. This allows us to take in more detailed information, and it can indicate quite a bit of meaningful information on the user’s attention and understanding. A shorter period of time before a user’s first fixation, for example, can indicate a high level of interest or attractiveness for that point. A fixation held for a long period of time can indicate that that aspect of the stimulus is very engaging or harder to understand. Visual-tracking technology, unfortunately, can’t tell which case is true, but there are other tools available to you that can supplement and explain the data you collected.
Another term you are likely to encounter is “fixation sequence.” This is the order and direction in which fixations occur, including data on where the user was looking as well as when they were looking at a specific point. A fixation sequence can help you understand what aspects of a stimulus the user prioritizes. One theme you may notice is that the user focuses on the center of an image at first — a phenomenon called central fixation bias.
Not only can visual tracking help you understand what a user finds interesting, but it can also help gather data on a participant’s eye movements. One type of eye movement that is often discussed in the medical application of eye-tracking technology is known as saccades. Saccades are rapid movements of the eyes from one point to another — or, to use another eye tracking term, from one fixation to another.
Saccades may be an unfamiliar term, but you are certainly familiar with the reality. Right now your eyes make small movements while reading, jumping from letter to letter. You also perform a similar movement – with larger jumps – when scanning a room. The eye movements that define the stage of sleep known as REM – the “rapid eye movement” stage – are also saccades.
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These are a few of the most basic terms you will come across in the field of visual tracking research, but they are certainly not the only vocabulary words you’ll want to learn. Look for part two of this series for more eye-tracking technology terms you should know, and find the software and hardware you need with Gazepoint! We have made our research-grade eye tracker available at a consumer price point so you can harness this innovative technology for your personal and professional goals. Whether you are a healthcare professional looking for new diagnosis techniques or a college professor who wants to offer your students hands-on experience and accurate data, the Gazepoint eye tracker is made for you. Place your order today to get started!