Students must take three rotations but can take more. During the nine months of the core curriculum, sufficient time is left for 16-20 hours of research each week. Incoming students are strongly encouraged to arrive at the start of the summer so that they can work full time in a lab for several months before courses start and also enjoy Portland's summer. Summer rotations are particularly useful for sampling the different off-campus research sites (Oregon Regional Primate Research Center). The primary purpose of the rotations is to experience different laboratories and research subjects so that you can intelligently choose a thesis lab. Another purpose is to learn a variety of scientific methods.
Choosing a thesis lab is important for more than just your graduate career. For the vast majority of working scientists, the choice of a their thesis lab determined the general area of science to which they now devote their lives. This certainly makes it one of the most important decisions of your career. In making the choice, consider your interest in the general field and in the particular research of a lab. Also, the nature of experimental methods and day-to-day life in different fields varies and should be considered in the decision. Rotations are offered primarily so that each student can sample a variety of different labs before committing to one.