A central premise of the discovery-learning and progressive education movements was that the child's own questions are the most appropriate starting point for instruction. Recent advances present new opportunities for discovery-oriented learning. This project has been attempting to create a classroom environment which affords students the opportunity to pose meaningful problems within the domain of a specific scientific challenge. One component of this environment is a brief videotape which invites students to generate problems which would have to be solved in order to carry out a mission to the planet Mars. Two studies explored several aspects of sixth graders' performance in this environment. In the first study, which involved 48 average/high ability suburban school students, the content of the problems which students posed was categorized, and changes in problems across three stages of the process were evaluated. In the second study, which involved low/average students from an inner city school, the effectiveness of the video was compared with a typical educational video about travelling to Mars. While these studies confirmed that these students are able to pose "educationally worthwhile" problems in this environment, it was concluded that more explicit guidance is needed. Proposals for providing this guidance and additional research questions are described. The appendix includes a figure describing the conceptual framework. (Contains 30 references.) (ALF)