From the Graduate School’s Programs and Policies [page 537]:
Because the Graduate School considers teaching experience to be an integral part of graduate education, doctoral students receive financial aid packages that include teaching fellowships. In many programs there are specific years when students are expected to teach. For example, most humanities and social science students will teach in their third and fourth years. In the natural sciences, the timing of teaching is earlier or is flexible across several years. When requested by the student for compelling academic reasons, these patterns may be adjusted with the permission of an associate dean and the director of graduate studies contingent on the student’s satisfactory academic progress and on sufficient course enrollment.
Students are required to serve as a teaching fellows for four semesters. Usually that translates to appointment as a TF4 in each semester of the third and fourth years. See Programs and Policies [page 537] for a description of the duties of teaching fellows at each level.
In cases where there is mutual agreement between the student and the DGS, one semester of the teaching requirement can be fulfilled during the second year. The 4 TF units can then be split across two courses. The Department encourages students to consider this option, both for the experience of seeing coursework from the teaching side and as a gentle way to revise basic concepts for the theory qualifying exam (if taken at the end of the second year)
The Graduate Teaching Center offers further ways for students to improve their teaching skills. For those seeking an academic career, the ability to teach well is essential.
- See https://gsas.yale.edu/academic-professional-development/teaching-fellow-program for more details about the Teaching Fellow Program and the teaching requirement.