Individual concepts of students comparing distributions

International audienceWhile distributions were long understood as " fundamental given of statistical reasoning " (Wild 2006, 10), recent research uncovered students' difficulties in acquiring the underlying conceptual structure and making statistically sustainable inferences when comparing distributions. Research so far describes informal strategies such as using 'clumps' as productive when learning to compare distributions. However, more insights are needed regarding why some of these strategies are chosen in certain situations in order to fully relate students' informal strategies to statistical concepts and measures in task design. This paper aims at clarifying the students' reasoning behind what to focus on for comparisons. We will present empirical snapshots from students in grade 8 (13–15 years old) who focus almost exclusively on absolute frequencies of dots and specifically determined intervals for comparing distributions