Eye-tracking is a contactless way of recording pupil and eye movements in order to assess psychological stain or operational suitability. Eye-tracking systems are optical measurement methods that can be used to examine pupil size, visual behavior or attentional focus when analyzing any one of a variety of questions.
At the IAW – Institut für Arbeitswissenschaft (Institute of Industrial Engineering and Ergonomics), eye tracking is used in laboratory and field environments to gain knowledge about the mental an emotional state of test subjects when experimental tasks are processed. This method makes it possible to evaluate whether a certain software can be used, or to analyze the efficiency of human-machine interaction. Important indicators to be recorded include the diameter of the pupil, the number of times and duration of the eyelid closing, fixations, and movements (saccades) of the eyes. This information can be used to indirectly draw conclusions about the difficulty of a task, for example, in addition to the person’s strain level. In this respect, an increase in pupil diameter indicates a greater degree of mental or emotional strain and a higher fixation duration, i.e. the length of time a certain stimulus remains in the focus of attention, which in turn results in more difficulty in incorporating information. Fixation duration can also be used to evaluate usability aspects, such as software menu structures or the structure and navigation of websites.
At the IAW we use both stationary eye tracking systems and eye tracking glasses. The stationary systems perform high-resolution analyses and collect data with great precision (millimeters) regarding usage behavior. Portable systems in the form of glasses, on the other hand, offer less precision but can be used under more natural conditions.