An explicit goal of the current reform movement in science education is to promote scientific literacy in the United States. One way to encourage scientific literacy is to help students develop a better understanding of science subject matter, that is, the declarative knowledge specifically associated with the physical, life, and earth sciences. However, in addition to helping students develop this type of knowledge, science education programs designed to promote true scientific literacy need to also help learners understand how this knowledge is generated, justified, and evaluated by scientists and how to use such knowledge to engage in inquiry in a way that reflects the practices of the scientific community. In this literature, inquiry is described as a knowledge-building process in which explanations are developed to make sense of data and then presented to a community of peers so they can be critiqued, debated, and revised. Thus, the ability to engage in argumentation in order to construct, justify, and evaluate scientific explanations is seen by many as an important component of scientific literacy. In order to foster productive argumentation in science classrooms, the authors have developed the personally seeded discussion (PSD). This article talks about PSD and its benefits. The PSD is an online asynchronous discussion forum that automatically sorts participants into small groups based on the nature of students' ideas. This tool is currently embedded into an online science project called "Thermodynamics: Probing Your Surroundings." (Contains 3 figures.)