Strangers, enemies, terms and taxonomies

It may be apocryphal, but I have been told that in some spoken languages the word for "stranger" is also the word for "enemy" -- to fail to make such a distinction must constrain one's behavior toward strangers. Likewise, our thinking on educational issues is constrained when we unaware of important distinctions. In the following paragraphs, I provide a potpourri of some my favorite terms and taxonomies that make important educational distinctions. I make no claim that these are the most useful distinctions. Instead, I merely seek to illustrate the importance of making distinctions.