Graphing in Groups: Learning About Lines in a Collaborative Classroom Network Environment

This article presents a design experiment in which we explore new structures for classroom collaboration supported by a classroom network of handheld graphing calculators. We describe a design for small group investigations of linear functions and present findings from its implementation in three high school algebra classrooms. Our coding of the problem-solving efforts of six student focus pairs in this environment over the course of several class sessions indicates that these students tended to move from exploratory and visual to more analytic means of establishing lines of a specified slope. As they adopted these analytic approaches, they were also more likely to enact their strategies jointly. In closer examination of emerging analytic strategies in episodes selected from the work of one of the pairs, we argue that the processes by which these students discovered the need for coordinated action on their respective points, and came to establish mathematical meaning for the relations between their coordinate locations as slope, were overlapping and intertwined.