This paper presents assessment data from a first-year writing library partnership to examine the relationship between student source use and written synthesis. It finds that first-year students could locate peer-reviewed, scholarly sources but that these sources were poorly integrated in their arguments--if they were used at all. In contrast, it finds that students attempted to synthesize their in-class reading material, suggesting that students "tack on" outside sources. Ultimately, this paper argues that librarians may want to consider shifting their instructional focus from traditional one-shot sessions to other solutions recommended by the literature.