09-07-2020, 05:09 AM
When people talk about eye-tracker accuracy, they're usually referring to spatial accuracy. This is often defined as the difference between the recorded gaze position and the person's true gaze position. However, because it's impossible to know the true gaze position perfectly, spatial accuracy is practically measured as the difference between the recorded gaze and the known position of a fixation target.
You can measure spatial accuracy by running a Validation procedure from the Camera Setup screen immediately after a successful calibration. The validation process reports the error for each target, along with the average and maximum error values across all targets. Typically for adults with normal vision, average error values range from 0.25 - 0.50 degrees. We generally recommend aiming for average error values of < 0.5 degrees and a maximum error of < 1.0 degrees. See What determines whether a validation is "GOOD", "FAIR" or "POOR"? for how the validation criteria.
Additional Resources
To learn more about measuring and maximizing spatial accuracy, please see the relevant setup and usage training videos:
You can measure spatial accuracy by running a Validation procedure from the Camera Setup screen immediately after a successful calibration. The validation process reports the error for each target, along with the average and maximum error values across all targets. Typically for adults with normal vision, average error values range from 0.25 - 0.50 degrees. We generally recommend aiming for average error values of < 0.5 degrees and a maximum error of < 1.0 degrees. See What determines whether a validation is "GOOD", "FAIR" or "POOR"? for how the validation criteria.
Additional Resources
To learn more about measuring and maximizing spatial accuracy, please see the relevant setup and usage training videos: