iTrace Core XML Format

<itrace_core session_id="" session_date_time="[timestamp_milli]" task_name="" researcher="" participant_id="">
    <environment screen_width="" screen_height="" tracker_type="" tracker_serial_number="" screen_recording_start="[timestamp_milli]"/>
    <calibration timestamp="[timestamp_milli]">
        <calibration_point x="" y="">
            <sample left_x="" left_y="" left_validity="" right_x="" right_y="" right_validity="" />
            ...
        </calibration_point>
        ...
    </calibration>
    <gazes>
        <response event_id="" core_time="[timestamp_milli]" tracker_time="" x="" y="" left_x="" left_y="" left_pupil_diameter="" left_validation="" right_x="" right_y="" right_pupil_diameter="" right_validation="" user_left_x="" user_left_y="" user_left_z="" user_right_x="" user_right_y="" user_right_z="" />
        ...
    </gazes>
</itrace_core>

NOTE: All screen based X and Y coordinates for gazes and calibrations are multiplied by the screen width and height respectively. Only real world user coordinates for X, Y, and Z are not modified

itrace_core tag attributes:

• session_id unique identifier for a recording session
• session_date_time start of session recorded as a UTC Unix style timestamp in milliseconds
• task_name name of the task associated with the recorded data (user provided)
• researcher name of the researcher administering the study (user provided)
• participant_id anonymous id associated with the participant (user provided)

environment tag attributes:

• screen_width width of display in pixels used for the study
• screen_height height of display in pixels used for the study
• tracker_type tracker used to record gaze data
  • Open Gaze 2.0: VALUE attribute on the ACK response tag from a <GET ID="PRODUCT_ID" /> request
  • TOBII PRO: Tobii.Research.IEyeTracker.DeviceName
• tracker_serial_number tracker serial number (unique ID)
  • Open Gaze 2.0: VALUE attribute on the ACK response tag from a <GET ID="SERIAL_ID" /> request
  • TOBII PRO: Tobii.Research.IEyeTracker.SerialNumber
• screen_recording_start if screen recording is enabled this represents the start time of the video as a UTC Unix style timestamp in milliseconds (otherwise 0)

calibration tag attributes:

• timestamp time when calibration was taken as a UTC Unix style timestamp in milliseconds

calibration_point tag attributes:

• x => x position of point used for calibration
  • API USED:
    • Open Gaze 2.0: CALX# attribute on the CAL Tag (# is 1 for the first calibration point and increases until the total number of calibration points is reached)
    • TOBII PRO: Tobii.Research.CalibrationResult.CalibrationPoints[#].PositionOnDisplayArea.X (# is 0 for the first calibration point and increases until total number of calibration points - 1 is reached)
• y y position of point used for calibration
  • API USED:
    • Open Gaze 2.0: CALY# attribute on the CAL Tag (# is 1 for the first calibration point and increases until the total number of calibration points is reached)
    • Tobii Pro: Tobii.Research.CalibrationResult.CalibrationPoints[#].PositionOnDisplayArea.Y (# is 0 for the first calibration point and increases until total number of calibration points - 1 is reached)

sample tag attributes:

• left_x x coordinate for left eye calibration sample
  • API USED:
    • Open Gaze 2.0: LX# attribute on the CAL Tag (# is 1 for the first calibration point and increases until the total number of calibration points is reached)
    • Tobii Pro: Tobii.Research.CalibrationResult.CalibrationPoints[#].CalibrationSamples[#2].LeftEye.PositionOnDisplayArea.X (# and #2 represent indices into the points and samples taken at each point respectively)
• left_y y coordinate for left eye calibration sample
  • API USED:
    • Open Gaze 2.0: LY# attribute on the CAL Tag (# is 1 for the first calibration point and increases until the total number of calibration points is reached)
    • Tobii Pro: Tobii.Research.CalibrationResult.CalibrationPoints[#].CalibrationSamples[#2].LeftEye.PositionOnDisplayArea.Y (# and #2 represent indices into the points and samples taken at each point respectively)
• left_validity left eye validity for calibration sample
  • API USED: *_ Open Gaze API 2.0:_ LV# attribute on the CAL Tag (# is 1 for the first calibration point and increases until the total number of calibration points is reached)
    • Tobii Pro: Tobii.Research.CalibrationResult.CalibrationPoints[#].CalibrationSamples[#2].LeftEye.Validity (# and #2 represent indices into the points and samples taken at each point respectively)
• right_x x coordinate for right eye calibration sample
  • API USED:
    • Open Gaze 2.0: RX# attribute on the CAL Tag (# is 1 for the first calibration point and increases until the total number of calibration points is reached)
    • Tobii Pro: Tobii.Research.CalibrationResult.CalibrationPoints[#].CalibrationSamples[#2].RightEye.PositionOnDisplayArea.X (# and #2 represent indices into the points and samples taken at each point respectively)
• right_y y coordinate for right eye calibration sample
  • API USED:
    • Open Gaze 2.0: RY# attribute on the CAL Tag (# is 1 for the first calibration point and increases until the total number of calibration points is reached)
    • Tobii Pro: Tobii.Research.CalibrationResult.CalibrationPoints[#].CalibrationSamples[#2].RightEye.PositionOnDisplayArea.Y (# and #2 represent indices into the points and samples taken at each point respectively)
• right_validity right eye validity for calibration sample
  • API USED:
    • Open Gaze 2.0: RV# attribute on the CAL Tag (# is 1 for the first calibration point and increases until the total number of calibration points is reached)
    • Tobii Pro: Tobii.Research.CalibrationResult.CalibrationPoints[#].CalibrationSamples[#2].RightEye.Validity (# and #2 represent indices into the points and samples taken at each point respectively)

response tag attributes:

• event_id unique id for the recorded gaze
• core_time timestamp when core recorded data in system time
• tracker_time time information from tracker API
  • API USED:
    • Open Gaze 2.0: TIME_TICK attribute on the REC Tag
    • Tobii Pro: Tobii.Research.GazeDataEventArgs.DeviceTimeStamp
• x screen based x coordinate
  • API USED:
    • Open Gaze 2.0: BPOGX attribute on the REC Tag
    • Tobii Pro: Average of X data for valid eyes Tobii.Research.GazeDataEventArgs.RightEye.GazePoint.PositionOnDisplayArea.X and Tobii.Research.GazeDataEventArgs.LeftEye.GazePoint.PositionOnDisplayArea.X
• y screen based y coordinate
  • API USED:
    • Open Gaze 2.0: BPOGY attribute on the REC Tag
    • Tobii Pro: Average of X data from valid eyes Tobii.Research.GazeDataEventArgs.RightEye.GazePoint.PositionOnDisplayArea.Y and Tobii.Research.GazeDataEventArgs.LeftEye.GazePoint.PositionOnDisplayArea.Y
• left_x screen based left eye x coordinate
  • API USED:
    • Open Gaze 2.0: LPOGX attribute on the REC Tag
    • Tobii Pro: Tobii.Research.GazeDataEventArgs.LeftEye.GazePoint.PositionOnDisplayArea.X
• left_y screen based left eye y coordinate
  • API USED:
    • Open Gaze 2.0: LPOGX attribute on the REC Tag
    • Tobii Pro: Tobii.Research.GazeDataEventArgs.LeftEye.GazePoint.PositionOnDisplayArea.Y
• left_pupil_diameter left pupil diameter from tracker
  • API USED:
    • Open Gaze 2.0: LPD attribute on the REC Tag
    • Tobii Pro: Tobii.Research.GazeDataEventArgs.LeftEye.Pupil.PupilDiameter
• left_validation left eye validation from tracker
  • API USED:
    • Open Gaze 2.0: LPOGV attribute on the REC Tag
    • Tobii Pro: Tobii.Research.GazeDataEventArgs.LeftEye.GazePoint.Validity
• right_x screen based right eye x coordinate
  • API USED:
    • Open Gaze 2.0: RPOGX attribute on the REC Tag
    • Tobii Pro: Tobii.Research.GazeDataEventArgs.RightEye.GazePoint.PositionOnDisplayArea.X
• right_y screen based right eye y coordinate
  • API USED:
    • Open Gaze 2.0: RPOGY attribute on the REC Tag
    • Tobii Pro: Tobii.Research.GazeDataEventArgs.RightEye.GazePoint.PositionOnDisplayArea.Y
• right_pupil_diameter right pupil diameter from tracker
  • API USED:
    • Open Gaze 2.0: RPD attribute on the REC Tag
    • Tobii Pro: Tobii.Research.GazeDataEventArgs.RightEye.Pupil.PupilDiameter
• right_validation right eye validation from tracker
  • API USED:
    • Open Gaze 2.0: RPOGV attribute on the REC Tag
    • Tobii Pro: Tobii.Research.GazeDataEventArgs.RightEye.GazePoint.Validity
• user_left_x real world x position of left eye
  • API USED:
    • Open Gaze 2.0: LEYEX attribute on the REC Tag
    • Tobii Pro: Tobii.Research.GazeDataEventArgs.LeftEye.GazePoint.PositionInUserCoordinates.X
• user_left_y real world y position of left eye
  • API USED:
    • Open Gaze 2.0: LEYEY attribute on the REC Tag
    • Tobii Pro: Tobii.Research.GazeDataEventArgs.LeftEye.GazePoint.PositionInUserCoordinates.Y
• user_left_z real world z position of left eye
  • API USED:
    • Open Gaze 2.0: LEYEZ attribute on the REC Tag
    • Tobii Pro: Tobii.Research.GazeDataEventArgs.LeftEye.GazePoint.PositionInUserCoordinates.Z
• user_right_x real world x position of right eye
  • API USED:
    • Open Gaze 2.0: REYEX attribute on the REC Tag
    • Tobii Pro: Tobii.Research.GazeDataEventArgs.RightEye.GazePoint.PositionInUserCoordinates.X
• user_right_y real world y position of right eye
  • API USED:
    • Open Gaze 2.0: REYEY attribute on the REC Tag
    • Tobii Pro: Tobii.Research.GazeDataEventArgs.RightEye.GazePoint.PositionInUserCoordinates.Y
• user_right_z real world z position of right eye
  • API USED:
    • Open Gaze 2.0: REYEZ attribute on the REC Tag
    • Tobii Pro: Tobii.Research.GazeDataEventArgs.RightEye.GazePoint.PositionInUserCoordinates.Z