Venn Diagrams

a young math book
by Robert Froman
illustrated by Jan Pyk
Crowell Company 1972

A picture book for older readers about Venn diagrams? Sure, why not.

I wasn't looking for this book but I saw it on a display shelf at the library and couldn't resist. With it's old school three-color 70's illustrations and the promise of kid-friendly statistical analysis, how could I resist?

The book eases in to the concept of grouping things before setting off to find commonalities and explaining how to diagram them. Beyond a simple visual, the book explains how to take raw data and sort it into overlapping circles with the simple math that goes with it.

All is well and good until the book moves to three circles and an example of a group of kids wanting two of three flavors each. The overlapping circles are established, followed by some discussion of what isn't possible, and then there are a couple trial-and-error examples before the solution is presented. The problem is that the book doesn't explain exactly how that final answer was was accomplished leaving the reader (and that means me) scratching their head trying to figure out a method for deducing this and similar equations.

That isn't necessarily a bad thing because learning shouldn't be an entirely passive activity. The problem is that the book continues with another three-circle diagram situation – and SAT word problem if ever there was one, concerning three suspects possibly sneaking a slice of pie – that not only allows the reader to fumble with trying to figure out the problem but actually hides a crucial bit of information that implicates a fourth suspect. Technically, yes, the diagram would accommodate the guilty party in the center, but to spend four pages explaining how to construct a Venn diagram only to say "Oops, guess we forgot to mention the one person who could complete the mystery" provides the sort of frustration that would turn off some kids to math and statistical analysis.

Barring its faults, I still wish someone had introduced me to Venn diagrams when I was young. A good introduction here on how they work and some practical applications for the future statistician, census taker, graphic artist, or nerdy kid who just likes finding ways to group things.