meta: Greek, meaning "beyond".

I think of it as "about". A meta-something is something about that something.

Hang on, I'm about to get less cryptic.

So for example, meta-data is data about data. You store a photo on flickr. That photo is data to flickr. But flickr also silently stores data about the data: its size, the time it was posted, so on. So, meta-data.

Say you want to improve your reading speed. You go out and buy a book on speed-reading. What are you doing? You are reading about reading. Very meta.

If you are a computer science geek, you know all about meta this and meta that. Programming: Writing a program that does stuff. Meta-programming: Writing a program that writes programs to do stuff. We've all done it. SQL that writes SQL? Been there.

Grammar is a meta-language, since it is a language that describes language. This particular example is even more interesting to me. Grammar describes English, and it is itself written in English. Since it is written in English, it must adhere to the rules of itself, otherwise we wouldn't understand it. Very very meta. Self-referential, even.

Cognition is the act of learning or knowing. So meta-cognition would be...you guessed it: learning about learning. I am doing it right now. I am reading a book about how we learn: Make it Stick, by Peter C. Brown.

More generally, it is a book about epistemology. Epistemology is the body of knowledge that tries to understand the nature of knowledge. So questions like: What is knowledge? How do we derive knowledge? And so on.

I came across this interesting example of meta-cognition in the book. Donald Rumsfeld, talking about Iraq in 2002, sums up meta-cognition thusly:

"There are known knowns; there are things we know that we know. There are known unknowns; that is to say, there are things that we now know we don’t know. But there are also unknown unknowns—there are things we do not know we don’t know."