Known Knowns, Unknown Knowns, and Unknown Unknowns

What you know and what you don't?

In February 2002, Donald Rumsfeld, the then US Secretary of State for Defence, stated at a Defence Department briefing¹:

There are known knowns; there are things we know we know.

We also know there are known unknowns; that is to say we know there are some things we do not know.

But there are also unknown unknowns — there are things we do not know we don’t know¹.

We will explore the knowns and unknowns of our situation.

known knowns — obvious context

In the obvious context, you know what type of situation you are dealing with and you know obvious approach to take.

A situation that might fit the obvious domain is reproducing paper airplanes. The paper airplane has been clearly defined; you know everything there is to know about how to create the paper airplane since a child. Now you…