I would like to find a book or some reliable source that explains how to teach the difference between a fact and an opinion. I would like this to appeal to as many people as possible, many ages, many backgrounds, and so on. So I have in mind something simple and direct. I thought there might be something elementary with which to start a discussion, but I'm uncertain where to look in the ocean of information.
It's been decades since I was in graduate school, so I'm not going to recount everything I've read. Recent attempts to answer this question have included asking teachers I know, doing an internet search for "fact", what is a fact, and what is the difference between a fact and an opinion; reading How to Think by Alan Jacobs and parts of The Portable Handbook of Critical Thinking by Richard Epstein. I found an entry for "fact" at the Stanford Encyclopedia of Philosophy at plato.stanford.edu which is fairly complicated.
