Visualizing the emergent structure of children's mathematical argument

Mathematics educators suggest that students of all ages need to participate in productive forms of mathematical argument (NCTM, 2000). Accordingly, we developed two complementary frameworks for analyzing the emergence of mathematical argumentation in one second-grade classroom. Children attempted to resolve contesting claims about the “space covered” by three different-looking rectangles of equal area measure. Our first analysis renders the topology of the semantic structure of the classroom conversation as a directed graph. The graph affords clear “at a glance” visualization of how various senses of mathematics—as imagined, as performed, and as historically rooted—were interrelated. The graph represents the emergence and intercoordination between conceptual and procedural knowledge in the ebb and flow of classroom conversation. The graph has not just descriptive, but also predictive power: Interconnectedness among the nodes of the graph representing the first 40 min of conversation predicted the structure of recall in the final ten minutes by children who had played little overt role in the conversation up to that point. The second, complementary framework draws upon Goffman’s expanded repertoire of roles in speech to demonstrate how the teacher orchestrated this classroom conversation to establish coherent argument. In this second analysis, we establish how the teacher mediated between the everyday talk of her students and the discourse of mathematics. Her revoicing of student talk created interstices for identity and participation in the formation of the argument. Together, the two forms of analysis illuminate the emergence of mathematical argument at two levels: as collective structure and concurrently, as individual activity. © 2001 Cognitive Science Society, Inc. All rights reserved. * Corresponding author. Tel.: 11-608-263-4295. E-mail address: [email protected] (R. Lehrer). http://www.elsevier.com/locate/cogsci Cognitive Science 25 (2001) 733–773 0364-0213/01/$ – see front matter © 2001 Cognitive Science Society, Inc. All rights reserved. PII: S0364-0213(01)00052-0