The program is structured by the guiding idea that linguistics is a unified discipline, with cross-fertilization between sub-disciplines a major source of growth and innovation. Students study each of the three core areas intensively over the first year and a half, and then specialize according to their interests. From the start, the curriculum is designed to facilitate original research: in addition to course-related work, students present two qualifying papers, written in close consultation with faculty, one at the end of the second year, the other at the end of the third year. Dissertation research and writing take up the fourth and fifth years. Students are encouraged to gain expertise in other areas related to linguistics. Many students work closely with faculty in Cognitive Psychology, Philosophy, or Computer Science.