Presenting science is an authentic activity of practicing scientists. Thus, effective communication of science is an important skill to nurture in high school students who are learning science. This study examines strategies employed by high school students as they make science presentations; it assesses students' conceptual understandings of particular science topics through their presentations and investigates gender differences. Data are derived from science presentation given by eight high school students, three females and five males who attended a summer science program. Data sources included videotaped presentations, ethnographic fieldnotes, interviews with presenters and members of the audience, and presenter notes and overheads. Presentations were transcribed and submitted to discourse analysis from an interactional sociolinguistic perspective. This article focuses on the methodology employed and how it helps inform the above research questions. The author argues that use of this methodology leads to findings that inform important social-communicative issues in the learning of science. Practical advice for teaching students to present science, implications for use of presentations to assess conceptual learning, and indications of some possible gender differences are discussed.