This study investigated the constraints students in an alternative education program encountered when attempting to implement their individualized curricula in the Independent Study Program (ISP) at the University of Illinois. The study used in-depth interviews with an informant sample of 10 ISP students to gather data about curriculum construction during the third and fourth years of undergraduate medical education. The ISP program within the College of Medicine at Chicago at UI allows undergraduate students to design their own curricula in two phases, pre-program (application and research project proposal subject to ISP approval) and implementation. The research found that students encountered little resistance during the pre-program phase and many constraints during implementation. The study concluded that curriculum construction and individualized program implementation in an institutional context is constrained by many factors. The requirements of the relatively inflexible, coexisting traditional curriculum, an implied lack of universal knowledge about the ISP and options available to its students, and the course access policies of instructional sites were constraining factors. While students were theoretically free to construct their curricula as they wanted they still had to operate in the practical and logistical constraints of institutional policies. A serious obstacle was also the resistance offered by course personnel to some forms of curricular individualization. (JB)