Research on physics problem categorization has established that proficient problem solvers are able to group together physics problems that would be solved by similar principles and use conceptual approaches when solving problems, whereas weak solvers rely more heavily upon surface features (objects, contexts, and quantities provided) to identify specific equations that match to the problem situation. This study explores the degree to which novices are able to shift their categorization strategies toward one that is more principle based as a result of a brief, computer-based intervention designed to highlight the role of principles as categorization criteria. Students finishing an introductory algebra-based mechanics course were presented with a sequence of problem pairs, asked to judge whether each pair would be solved similarly, and provided with feedback. Students in one condition received feedback that was very sparse and only indicated correctness, whereas students in a second condition viewed elaborate feedback that linked problem features to the appropriate concepts and principles to solve each problem. We found an increased use of physics principles in the reasoning provided by students who received the elaborate feedback whereas students who did not view this elaboration primarily cited quantities in the problem statement. Although these results suggest it is possible to increase students' attention to principles when approaching problems, poor performance on the items indicates that considering the appropriateness of principles remains a difficult task for beginning physics students.