This Level 1 Engaged Student Learning project aims to serve the national interest by enhancing our understanding of physics students' problem-solving skills, thereby ensuring they can go on to form the next generation of STEM professionals in the workforce. Specifically, this project investigates how students are able to use problem-solving tools such as diagrams, sketches, and graphs to solve novel physics problems to which they do not know the answers. This type of dynamic problem solving is a cornerstone of physics as a discipline, and is what industry employers often cite as a key skill that physics degree holders bring to the table. By investigating the role of a key problem-solving skill - the ability to generate, interpret, and utilize multiple ways of representing information in the context of unfamiliar problems - this project has the potential to significantly enhance the ability of the educational system to train students to ensure their fluency with these skills. This project utilizes recent advances in eye-tracking technology to accomplish a goal previously unachievable due to both hardware and software limitations. Using eye-tracking glasses, this project will investigate how students spontaneously generate and utilize multiple forms of representations when solving physics problems. Specifically, this project will research three aspects of physics problem solving: 1) initiation of representation, 2) reference and utilization, and 3) effect of representation