Abstract
As part of a larger project studying school students' understanding of statistical variation,
92 students in grade 7 and 90 students in grade 9 participated in a unit of work related to the
chance and data curriculum, emphasising variation with respect to the topics covered.
Students completed pre- and post-tests devised to assess understanding before and after the
lessons in the unit. This paper reports on the teaching arrangements for the classes taking
part and the change in performance after the unit.
Jane M. Watson & Ben A. Kelly