“…Eye tracking instruments can collect a plethora of information, mainly focusing on subtle details of eye movements and fixations, e.g., the location and duration when a person looks at the visual material. , By analysis of eye tracking data, information on the participant’s attention can be obtained, which has been shown to be related to his/her cognitive processes. − The duration and number of eye fixations on a specific location of a visual scene often imply the importance or complexity of the location considered by the participant, ,− while the sequence of fixations indicates the dynamic patterns of visualization and cognitive processing strategies. , Eye tracking seemed uniquely capable of observing various problem-solving strategies in action in a way that other methods like interviews or correct-answer correlations may not be able to capture. In the last two decades, eye tracking technologies have been applied in studies of visual attention and comprehension ,,− as well as problem solving. ,,− Researchers have found different eye movement patterns for experts compared with novices when they read and/or solve problems. ,,, More recently, eye tracking research has gained popularity in the natural sciences discipline-based research community. Physics education research (PER) has used eye tracking to study troubleshooting or problem solving of circuits, , troubleshooting of mechanical devices, how spatial ability affects understanding of kinetics graphs and motion problems, and students’ use of conceptual information when solving mechanics-related problems .…”