Students are supported from three sources, in roughly equal numbers: fellowships (either from outside sources or departmental funds), Assistantships in Research (AR) in both theory and experiment, and Assistantships in Instruction (AI). All students remain supported by these sources for as long as they continue to make progress toward their degree . An AR requires 20 hours per week in an active research group; an AI up to 20 hours of work per week. Both ARs and AIs provide a stipend to the student and all tuition. All first-year students are awarded a university fellowship, unless they bring their own external fellowship. Students are encouraged to join a research group as soon as they arrive, in order to participate actively in the activities of the department. This is an opportunity to explore a possible thesis area, to begin actual thesis research, to develop useful technical skills, or to do the generals experimental project. The Department expects students to find summer support in a research group for the summer following the first year for all interested students in experimental fields. We will attempt to match the summer position with the interests of the student based on the student's application. The student is not obligated to accept this position and can seek another if desired. Most second year students are involved in teaching as AIs. Almost all of the AI positions involve contact with students. As well as being a valued service to the Department, the AI is a valuable experience for graduate students, as teaching of some kind is a part of many scientific careers. For this reason, students with outside fellowships are encouraged to volunteer for part-time teaching, for which a supplementary stipend is usually awarded.
Once they are fully involved in thesis research, most students are supported as ARs in the research groups of their thesis advisors. The work done for the AR is the student's thesis work itself. There is no summer academic session at Princeton, but the research program continues vigorously year-round. For most students, summer support is available. Some students use the summer months to study at an advanced summer school in the U.S. or abroad. When judged to be valuable for the student by his or her advisor, a departmental matching fund is available for such summer schools or for students to attend professional meetings or conferences.