Hi Bill!
I would like to use hatplots to identify and formalize “modal clumps” in a distribution. We use this in a teaching unit for grade 4. I really like the transition from modal clumps (with the drawing tool in CODAP) to an informal hatplot (with all the metaphors) to prepare the notion of a boxplot (we do not teach boxplots in grade 4 but we connect to hatplots when we teach boxplots later in school).
Susanne