At the beginning of their second year, students are asked to propose two research projects deriving from their current interests. One project will serve as the basis for the student's thesis work. The other should be in an area requiring a very different experimental approach from the first. The proposals define the problems, propose different and realistic experimental approaches and weigh the merits of each approach. These written proposals serve as the basis for an oral examination before three faculty members in which the student defends the feasibility and value of the experiments.