Accuracy and precision test method for remote eye trackers

Tobii has created a method to test the gaze accuracy and precision measurements of remote eye trackers.

Henrik Eskilsson, CEO of Tobii Technology says, “It is difficult for researchers to understand the technical specifications of remote eye trackers as each manufacturer uses its own definitions. The lack of a standard for measuring remote eye tracker performance makes a fair and balanced comparison impossible. We want to change that by introducing an objective test method that allows researchers to repeat the tests themselves and to judge the quality of the products.”

In order to facilitate interpretation of the specifications and provide an objective way to adequately compare different eye tracking systems, it is imperative that the same method is used and each metric is clearly described. In other words, the tests must follow the same protocol, use participants drawn from similar populations (or use standardized artificial eyes), perform measurements in the same environmental conditions, and analyze data in a standard and consistent way.

“We encourage customers and other manufacturers to use the test method to accumulate transparent information that makes comparison between different remote eye trackers possible”, says Eskilsson. “A uniform test method is an important instrument in the effort to continuously optimize eye tracking technology and deliver eye trackers of high quality.”

The method is extensive as it takes a variety of likely user scenarios into consideration. The test specification includes ideal measurement conditions, large gaze angles, and different illumination sets and head positions in the head movement box. This ensures that the values specified in this method are as close as possible to those actually used in a real eye tracking session, where a test person is allowed to move freely within the perimeter of the head movement box.

Precision is also measured on artificial eyes in order to differentiate between system noise and precision of human eyes. Accuracy and precision are calculated from eye tracking data with high trackability that is verified in real time. Both metrics are presented based on monocular (dominant eye) and binocular data. An open source software tool developed especially for accuracy and precision measurements is supplied with the method to simplify the tests. The software is free for anyone to use.

In addition to the test method, the test results for the Tobii T60XL Eye Tracker and the test results for the Tobii X1 Light Eye Tracker are also available. All Tobii remote eye trackers will be measured using the test method, and more test reports will be made available at this site.

> Accuracy and Precision Test Method for Remote Eye Trackers

> Accuracy and Precision Test Report Tobii T60XL Eye Tracker

> Accuracy and Precision Test Report Tobii X1 Light Eye Tracker