Professor Frank's primary field of research is the history, literature, and doctrines of the Karaites, an ancient Jewish sect which does not accept the authority of the Talmud.  His other areas of expertise include medieval Jewish history, literature, and culture, especially Judeo-Arabic literature and biblical exegesis. He teaches Biblical Hebrew Literature in Translation, The Medieval Jewish Experience, Ancient and Medieval Jewish Civilization, Introduction to Jewish Studies, and Readings in Rabbinic Literature. He served as the Reviews Editor for the Journal of Jewish Studies. Among his publications are Search Scripture Well: Karaite Exegetes and the Origins of the Jewish Bible Commentary in the Islamic East (2004) and two edited volumes: The Jews of Medieval Islam: Community, Society, and Identity (1995); and (with Professor Matt Goldish), Rabbinic Culture and Its Critics: Jewish Authority, Dissent, and Heresy in Medieval and Early Modern Times (2008).