getEyeTracker(id).calibrate(threshold) (since PennController 1.8)
or getEyeTracker(id).calibrate(threshold,attempts)
Calibrates the eye-tracker so that threshold% of the estimated looks fall on the target.
If the eye-tracker was calibrated before, this command will display a button at the center of the page: after clicking it, participants must fix it for 3s. If fewer than threshold% of the estimated looks fall on the button during those 3s, or if the eye-tracker was not calibrated before, participants will be asked to click on 9 buttons placed along the edges of the page, to help calibrate the eye-tracker.
Execution of the trial’s script is paused until a calibration phase is successful, or after attempts failed calibration phases if a second parameter was provided.
It is recommended that you use this command at the beginning of each eye-tracking trial to ensure that the eye-tracker has a uniformly good calibration level throughout the experiment.
Example:
[js highlight=”4,15″ try=”data”]newTrial( newButton(“Start”).print().wait(newEyeTracker().test.ready()) )
newTrial(
newEyeTracker(“tracker”).calibrate(70)
,
newText(“Left”).css(“padding”,”20vw”).print(“20vw”, “40vh”),
newText(“Right”).css(“padding”,”20vw”).print(“60vw”, “40vh”)
,
getEyeTracker(“tracker”).add( getText(“Left”) , getText(“Right”) ).start()
,
newSelector().add( getText(“Left”) , getText(“Right”) ).wait()
)
newTrial(
newEyeTracker(“tracker”).calibrate(70)
,
newText(“Right”).css(“padding”,”20vw”).print(“20vw”, “40vh”),
newText(“Left”).css(“padding”,”20vw”).print(“60vw”, “40vh”)
,
getEyeTracker(“tracker”).add( getText(“Left”) , getText(“Right”) ).start()
,
newSelector().add( getText(“Left”) , getText(“Right”) ).wait()
)[/js]
Will go through a calibration phase at the beginning of the first eye-tracking trial. The second eye-tracking trial will begin with a central button: if fewer than 70% of the estimated looks fall on the button during the 3s fixation time-window, it will go through a calibration phase again.