Documentation, part 4:
The thorny issue of Common Knowledge

We all know that there's no need to use a footnote for information that's widely known, or "common knowledge." But how do you know for sure when a bit of information is REALLY common knowledge?

The rule of thumb is that if you find the same fact in three reputable sources, then it's fine to drop the footnote--being sure that at least one of those sources is in your final bibliography.

This is fine, but it doesn't take human nature into account. We humans have a way of latching on to a source or viewpoint that makes sense to us, and disregard other viewpoints as irrelevant. . . . that is, until it gets to the point that we can no longer ignore the other voices.

Tho NOT required, there's a method to counteract this limitation in human nature, a method that at first may seem absurdly laborious. But it's good craftsmanship, will keep you out of trouble, and has the potential to improve your credibility. As you become more experienced in your field, you'll need it only when you move into new territory. But it's a good idea to use it at first--and it's not hard if you have organized your notes well.

The method and rationale follow on the next two pages.

The final step in writing a paper is of course preparing the final version of your paper. You may want to skip ahead to this step and then return to the issue of common knowledge.