Theoretical and empirical research on argument and argumentation in science education has intensified over the last two decades. The term argument in this review refers to the artifacts that a student or a group of students create when asked to articulate and justify claims or explanations whereas the term argumentation refers to the process of constructing these artifacts. The intent of this review is to provide an overview of several analytic frameworks that science educators use to assess and characterize the nature of or quality of scientific arguments in terms of three focal issues: structure, justification, and content. To highlight the foci, affordances, and constraints of these different analytic methods, the review of each framework includes an analysis of a sample argument. The review concludes with a synthesis of the three focal issues and outlines several recommendations for future work. Ultimately, this examination and synthesis of these frameworks in terms of how each conceptualizes argument structure, justification, and content is intended to provide a theoretical foundation for future research on argument in science education. (Contains 7 figures, 3 tables, and 1 footnote.) [An earlier version of this article, entitled "Assessment of Argument in Science Education: A Critical Review of the Literature," appeared in S. A. Barab, K. E. Hay, & D. T. Hickey (Eds.). (2006). "Proceedings of the Seventh International Conference of the Learning Sciences--Making a Difference' (p 655-661). Mahwah, NJ: Erlbaum.]