Enhancing students' graph interpretation abilities through the use of graphing calculators

The purpose of this study was to determine (1) the strategies students use when asked to interpret contextual graphs of functions both locally and globally; (2) the types of errors and misconceptions students exhibit when asked to interpret contextual graphs of functions both locally and globally; (3) the extent to which participation in probe-based graphing calculator activities reduce students' graph interpretation misconceptions and errors.;A total of six eighth-grade students enrolled in Algebra 1 at a private middle school for girls were the participants in this study. Each student was interviewed prior to and then following an eleven-session classroom intervention. All interviews lasted approximately one-hour and were videotaped. During these interviews the participants completed a series of contextual graph interpretation tasks. Some of the tasks had been developed for use in previous research while others were specifically developed for this study.;Individual case studies for each participant were developed. These case studies detail the strengths and weaknesses each participant exhibited interpreting contextual graphs, both locally and globally, during their pre-intervention interviews and the improvements they demonstrated when completing the analogous post-intervention interview tasks.;The major findings included: participants in this study exhibited varying degrees of graph interpretation difficulties and misconceptions when completing both the pre- and post-intervention interview tasks; participants' abilities to locally and globally interpret contextual graphs improved by varying degrees following the classroom intervention; participants more carefully attended to axes variable greatly reducing the number of instances of iconic translations; participants exhibited more well developed understandings of the relationship between slope and the rate of change of one variable with respect to another following the intervention; and participants' post-intervention interview graph interpretations were more sophisticated incorporating language not used during their pre-intervention interviews.