Argumentation is vital in the development of scientific knowledge, and students who can argue from evidence and support their claims develop a deeper understanding of science. In this study, the Argument-Driven Inquiry instruction model was implemented in a two-semester sequence of introductory biology laboratories. Student's scientific argumentation sessions were video recorded and analyzed using the Assessment of Scientific Argumentation in the Classroom observation protocol. This protocol separates argumentation into three subcategories: cognitive (how the group develops understanding), epistemic (how consistent the group's process is with the culture of science), and social (how the group members interact with each other). We asked whether students are equally skilled in all subcategories of argumentation and how students' argumentation skills differ based on lab exercise and course. Students scored significantly higher on the social than the cognitive and epistemic subcategories of argumentation. Total argumentation scores were significantly different between the two focal investigations in Biology Laboratory I but not between the two focal investigations in Biology Laboratory II. Therefore, student argumentation skills were not consistent across content; the design of the lab exercises and their implementation impacted the level of argumentation that occurred. These results will ultimately aid in the development and expansion of Argument-Driven Inquiry instructional models, with the goal of further enhancing students' scientific argumentation skills and understanding of science.