This study investigates the types of sources that English composition students use in their research essays. Unlike previous studies, this project pairs an examination of source citations with deeper analysis of source use, and both are discussed in relation to responses gathered in focus groups with participating students and teachers. The researchers examine how students negotiate locating and using source material, particularly online sources, in terms of timeliness, authority, and bias. The researchers report on how teachers struggle to introduce these concepts and how students fail to perceive authority and bias in their sources.