Self-regulated learning with authentic and complex problems requires that learners observe their own learning and use additional information when appropriate (e.g., hypertextual information in computer-supported learning environments). Research indicates that learners in problem-based environments often have difficulties using additional information adequately, and they should be supported. Two studies involving a computer-supported, problem-based learning environment within a medical school analyzed the effect of strategy instruction on the use of additional information and the quality of the problem representation. In study 1, an expert model was used as strategy instruction. Two groups were compared: a group with strategy modeling and a group without. Strategy modeling influenced learners' frequency of looking up hypertextual information but did not influence the quality of their problem representations. This could be explained by difficulties in applying and contextualizing the general hypertext information to the problem. In study 2, the additional information was presented in a more contextualized way as a graphical representation of the case and its relevant concepts. Two groups were compared: a group with strategy instruction text and a group without. Strategy instruction texts supported an adequate use of this graphical information by learners and had an effect on the quality of problem representation. (Contains 29 references.) (Author/SM)