Supporting Students' Ways of Reasoning about Data.

OUR purpose in this article is to describe how one group of students came to reason about data while developing statistical understandings related to exploratory data analysis. In doing so, we will present episodes taken from a seventh-grade classroom in which we conducted a twelve-week teaching experiment. (The first two authors shared teaching responsibilities during the teaching experiment.) One of the goals of the teaching experiment was to investigate ways to support middle school students’ development of statistical reasoning proactively. Our interest was piqued by current debates about the role of statistics in school curricula (National Council of Teachers of Mathematics 1989, 1991; Shaughnessy 1992). The image that emerged for us as we read this literature was that of students engaging in instructional activities in which they both developed and critiqued data-based arguments. As we worked to develop an instructional sequence, we viewed the use of computer tools as an integral aspect of statistical reasoning rather than as technological add-ons. As such, the two computer tools we designed were intended to support students’ emerging mathematical notions while simultaneously providing them with tools for data analysis. In the twenty-first century, access to information will continue to be enhanced by new technologies. This fact highlights the importance of providing students with