Sampling tasks and sampling distributions provide a fertile realm for investigating students' conceptions of variability. A project-designed teaching episode on samples and sampling distributions was team-taught in 6 research classrooms (2 middle school and 4 high school) by the investigators and regular classroom mathematics teachers. Data sources included survey data collected in 6 research classes and 4 comparison classes both before and after the teaching episode, and semistructured task-based interviews conducted with students from the research classes. Student responses and reasoning on sampling tasks led to the development of a conceptual lattice that characterizes types of student reasoning about sampling distributions. The lattice may serve as a useful conceptual tool for researchers and as a potential instructional tool for teachers of statistics. Results suggest that teachers need to focus explicitly on multiple aspects of distributions, especially variability, to enhance students' reasoning about sampling distributions.
Jennifer Noll, Fariborz Maseeh Department of Mathematics and Statistics, Portland State University, PO Box 751, Portland, Oregon, 97207; email@example.com
J. Michael Shaughnessy, Fariborz Maseeh Department of Mathematics and Statistics, Portland State University, PO Box 751, Portland, Oregon, 97207; firstname.lastname@example.org