AbstractThis exploratory study examines how a series of laboratory activities designed using a new instructional model, called Argument‐Driven Inquiry (ADI), influences the ways students participate in scientific argumentation and the quality of the scientific arguments they craft as part of this process. The two outcomes of interest were assessed with a performance task that required small groups of students to explain a discrepant event and then generate a scientific argument. Student performance on this task was compared before and after an 18‐week intervention that included 15 ADI laboratory activities. The results of this study suggest that the students had better disciplinary engagement and produced better arguments after the intervention although some learning issues arose that seemed to hinder the students' overall improvement. The conclusions and implications of this research include several recommendations for improving the nature of laboratory‐based instruction to help cultivate the knowledge and skills students need to participate in scientific argumentation and to craft written arguments. © 2010 Wiley Periodicals, Inc. Sci Ed 95: 217–257, 2011