My son's texbook mostly uses inclusion - that seems "natural" to me and always has, its the way I was taught. One exception is "kite" versus "rhombus".
Now why would that exception be made?
Perhaps answering that question is as important as the rest. And being flexible enough to see that different defnitions could be made and everything still works out fine. What are the considerations in leaning one way versus another? My son can entertain those sorts of thoughts. Once that stage is reached, its of far lesser concern what road is actually taken.
Also, Venn Diagrams of course are indispensible here.
- ----- Original Message ----- From: "Robert Hansen" <firstname.lastname@example.org> To: <email@example.com> Sent: Monday, March 15, 2010 4:33 PM Subject: Re: Inclusive and exclusive definitions... again!
> It is a coincidence that my son is working with this exact situation. I provided some inclusion (and he is getting it) but not too heavy. Generally though, with many of these things, exclusion applies. We can technically gather up everything and build a tree but I find that in a natural setting one thinks more often in an exclusive fashion because it partitions and balances the knowledge more effectively. It's all the leaves gathered on each of the branches that we work with. Not so much the bare tree.