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Introduction. Processing Verbal Information in Concept Maps. How people read concept maps in the context of a semantically meaningful task?. Eye tracking. How do we see?. Fixations – visual gaze on a single location; 200-350 ms Saccades – fast movement of the eye
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Introduction Processing Verbal Information in Concept Maps How people read concept maps in the context of a semantically meaningful task?
Eye tracking How do we see? Fixations – visual gaze on a single location; 200-350 ms Saccades – fast movement of the eye Constant state of vibration at a rate of 30-70 Hz
Eye tracking How does it work? Infrared light source to illuminate the eye Sensor to capture a reflection of the user’s eye Calculating the gaze
Eye tracking Tobii T120 Data rate 120Hz Accuracy 0.5 degrees Drift 0.1 degrees Head movement box 30 X 22 cm at 70 cm Blink tracking recovery max 8 ms
Eye tracking Data output Timestamp - in milliseconds GazePointXRight - horizontal screen position of gaze Event – automatic and logged mouse clicks and keys Data1 – Data field for the event
Eye tracking Replay
Eye tracking Data output/AOI Fixation length - in milliseconds Fixations – number in AOI Total time – in AOI in milliseconds Time to first fixation – in milliseconds
Eye tracking Visualizations
Eye tracking Visualizations
Eye tracking Visualizations
Eye tracking Logged data
Experimental Design Concept Maps
Look “next” • Connected • Go to node with arrowheads • Go to node with reverse arrowheads • Distance • Size of node
Concept Map “Model” Assume: • Every sequence starts at N • Track each sequence until Terminal Event • Keep track of whether it was a First Visit or a Return Visit
Concept Map “Model” Assume: • Every sequence starts at N • Track each sequence until Terminal Event • Keep track of whether it was a First Visit or a Return Visit