This dissertation examines the epistemological moves made by Washington State University undergraduates in their general education course writing and during two impromptu writing assessment exams administered by the WSU writing program. It builds from previous interview-based research on epistemological change (Perry, 1998; diSessa, 1993; Vosniadou, Vamvakoussi & Skopelleti, 2008; Baxter Magolda, 2002; Baxter Magolda & King, 2012), applying the framework of conceptual change theory to the changes in knowledge use undergraduates demonstrate in their writing. To mark knowledge use and measure change, a coding schema was developed based on the researcher's experience with undergraduate writing, on Marcia Baxter Magolda's theory of self authorship (Baxter Magolda & King, 2012) and Nigel Harwood's research on the functions of academic citations (Harwood, 2010). Coders--themselves composition instructors and expert readers of student writing--were recruited to process over 600 pieces of student writing, resulting in over 31,000 coded statements. This study found that in the first two years of the undergraduate experience (when much of the average WSU student's general education coursework is completed), epistemological growth occurs in limited ways. While the broader sources of knowledge (e.g. the self, external authorities, internalized knowledge) preferred upon entering college seem to also be the preferred sources in the junior year, subtle qualitative changes can be observed in the authority students demonstrate over that knowledge, such that external authorities or internalized knowledge are used to extend larger arguments, rather than simply demonstrate that a piece of knowledge exists. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]