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How do I resolve difficulties with calibrating the eye tracker?

 

Difficulties calibrating the eye tracker. 

Calibration can sometimes be difficult for a variety of reasons:

  • The pupil wears glasses with thick frames and lenses. If this is the case, ask the pupil to keep their head still during calibration so that the glasses do not disturb the signal. Please ensure the lenses are clean.
  • Powerful light sources or strong sunlight may prevent the eye tracker from properly detecting the eyes. Move the equipment to a darker room, move away from windows or close any blinds which might be causing the issue.
  • The pupil has difficulty focusing on the moving circle. Encourage the pupil as they try to follow the moving circle around the screen with their eyes. They always need to stay focused on the circle even though they know where it is going, and they must continue to watch the circle as it stops in each corner.
  • The pupil may have a visual impairment, or they may have challenges around remaining focused.
  • Sometimes, for unknown reasons, it can be difficult to achieve a good calibration and it can be problematic despite several attempts. If this is the case, poor calibration must be accepted. Continue with the test and add a comment at the end. It is still possible to get a result despite a poor or incomplete calibration. Try a maximum of three times before continuing with the test.

    Examples of different quality calibration results:

    Optimal

    Two lines inside all circles

     

    Intermediate

    Lines within 4 out of the 5 circles

     

    Poor Calibration

    Lines are too long outside of the circles. Only accept this result after trying to calibrate a maximum of three times. Add a comment at the end of the test.

     

    Incomplete Calibration

    The two circles at the bottom are not visible as they lack lines. This means the pupil’s eyes were not detected at these points. Check positioning! Only accept this result after trying to calibrate a maximum of three times. Add a comment at the end of the test.

    Click here for more information about calibration.