Validation Screen; Figure 2-5: Example Validation Screen - SR Research EyeLink Portable Duo User Manual

2.4.3 Validation Screen

2.4.3.1 Validation Screen Purpose
The Validation screen displays target positions to the participant and measures
the difference between the target position and the computed fixation position for
the target based on the calibration model. Spatial error is reported in degrees of
visual angle, and can reflect both the adequacy of the initial calibration model,
and the participant's ability to refixate the targets during validation. The
functionality available in the Validation screen is very similar to that of the
Calibration screen.
Validation should only be performed after Calibration.
To perform a validation, have the participant look at the first fixation point and
press the 'Accept Fixation' button, or the ENTER or Spacebar key, to start the
validation. If 'Auto Trigger' is not enabled, you'll need to accept the target
fixation manually.
If the accuracy at a fixated position is not acceptable, you can press the
backspace key to go back and repeat a point. If you continue to press
backspace you will go further back in the calibration routine to repeat even
older points. If you are not satisfied with the calibration results you may choose
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Figure 2-5: Example Validation Screen