Test results from the Program for International Student Assessment (PISA) reveal that Shanghai students performed less well in solving interactive problems (those that require uncovering necessary information) than in solving analytical problems (those having all information disclosed at the outset). Accordingly, this study investigates information-processing strategies in solving these two types of complex problems. High- and low-performing students' eye fixations within certain areas of interest (AOIs) as well as their visits between AOIs were recorded as they solved problems on a computer. High-performing students had long fixation durations for the analytical problem and the problem-solving stage of the interactive problem. With regard to the problem exploration stage of the interactive problem, high-performing students had short fixation durations. These findings demonstrate how students had varying information-processing strategies for different types of problem-solving scenarios at different problem-solving stages. The implications of this study are discussed.