Analyzing tools: perspectives on the role of designed artifacts in mathematics learning / Anna Sfard, Kay Mclain -- Appendix: the object and the context: what are data are and where they come from / Kay McClain -- Reasoning with tools and inscriptions / Paul Cobb -- Teacher's and students' understanding: the role of tools and inscriptions in supporting effective communication / Kay McClain -- Orchestrating the multiple voices and inscriptions of a mathematics classroom / Ellice Ann Forman, Ellen Ansell -- Children's developing mathematics in collective practices: a framework for analysis / Geoffrey B. Saxe -- Representational tools and mathematical understanding / Analโucia D. Schliemann -- The interplay of intimations and implemenations: generating new discourse with new symbolic tools / Anna Sfard -- Fruits of polyphony: a commentary on a multiperspective analysis of mathematical discourse / Bert van Oers -- Appreciating the complexity of teaching and learning in school: a commentary on Cobb; Forman and Ansell; McClain; Saxe; Schliemann; and Sfard / Magdalene Lampert -- Diversity and commonality in the analysis of talk / Neil Mercer -- A commentary on instructional design / Douglas Macbeth -- Announcement