Firstly, Raphael uses intelligent screenshots to sustainably improve the work of usability experts with eye-tracking. Instead of having to watch lengthy video recordings of each user, his method creates intelligent screenshots for evaluation that nevertheless accurately depict the dynamics of modern websites. These intelligent screenshots allow usability experts to more quickly and effectively analyze eye-tracking data on websites - and thus provide an in-depth analysis of the experience on the website. Secondly, Raphael describes his work on the gaze-only Web browser "GazeTheWeb", which was evaluated by thirty subjects with motor impairments over a month-long international field study - with face-to-face interviews and via usage behavior. His work has produced fundamental insights into visual understanding of webpages and interaction with eye tracking on the Internet, which now find their application in Semanux.
The reviewers of the dissertation have covered the interdisciplinary spectrum of Raphael's research with their expertise: Prof. Dr. Steffen Staab as supervisor and the first reviewer with his expertise in Web Science, Prof. Dr. Andreas Bulling with his expertise in Human-Computer Interaction, and Prof. Dr. Dietrich Paulus with his expertise in Image Processing. Overall, the dissertation was graded magna cum laude, i.e., very good.