[1] A professor emeritus at the University of Pennsylvania,[2][3] he specialized in religious folklife and the study of belief.
Taking inspiration from scholarship and museum practice in Germany and particularly Scandinavia (Volkskunde[7]), they used the term "folklife" – distinguished from "folklore" – to describe this all-encompassing view.
[9] Yoder was key to the creation of the university's Department of Folklore and Folklife,[5] where his colleagues included MacEdward Leach (who he took over from as Head of Department in 1966), Dell Hymes, Henry Glassie, Barbara Kirshenblatt-Gimblett, John Szwed, Roger Abrahams, Dan Ben-Amos, Kenneth S. Goldstein, Margaret Mills, and Regina Bendix (and Anthony F.C.
[9] Yoder wrote about many aspects of folklife studies, specializing in religion, religious music, Fraktur, foodways, costume, and other material culture.
[11] He also regularly conducted research in Europe, especially Germany and Switzerland, the ancestral homelands of many Pennsylvania cultures.
When the American Folklife Center was founded six years later, Yoder was named as one of its original Trustees.