In this description of phenomenography, we take a functional view of the theoretical underpinnings that have traditionally been used to support its trustworthiness as a qualitative research approach. The chapter has two objectives, first to serve as an introduction for those considering embarking on research with a phenomenographic framing, and second to enable the recognition of the quality and scope of the knowledge claim inherent in phenomenographic outcomes. [For the complete volume, "Theory and Method in Higher Education Research. International Perspectives on Higher Education Research. Volume 9," see ED595152.]