Introduces a special issue on the ways in which symbolic tools enable, mediate, and shape mathematical thinking while being themselves a product of these processes. (Author/MM)

Describes the provenance of the data used in this issue. Includes design of the instructional sequence, instructional activities, classroom structure, and classroom episodes. (Author/MM)

Investigates not only the influence but also the confluence of students' and teacher's understandings of the quality of whole class discussions. Focuses on the communication between students and the teacher in the classroom. Considers the role of tools in both supporting and constraining communication in the classroom. (Author/MM)

Describes a methodology for analyzing the collective learning of the classroom community in terms of the evolution of classroom mathematical practices. In developing the rationale for this approach, grounds the discussion in work of mathematics educators who conduct classroom-based design research. Frames sample analysis as a paradigm case in…