Whorf took Sapir's first course at Yale on "American Indian Linguistics". He enrolled in a program of graduate studies, nominally working towards a PhD in linguistics, but he never actually attempted to obtain a degree, satisfying himself with participating in the intellectual community around Sapir. At Yale, Whorf joined the circle of Sapir's students that included such luminary linguists as Morris Swadesh, Mary Haas, Harry Hoijer, G. L. Trager and Charles F. Voegelin. Whorf took on a central role among Sapir's students and was well respected.