By some strange mental processes, and a fortuitous Google search, this led me to the Poetry & Philosophy of Donald H Rumsfeld, as exposed to the world by Hart Seely, initially in Slate in April 2003, and now published in a book, “Pieces of Intelligence”, by Seely. These poems are well worth a look for their own particular delight, but the one I was looking for you will probably have heard of in various guises, The Unknown:
‘As we know,Now this insightful (!) poem (set to music by Bryant Kong, available at http://www.stuffedpenguin.com/rumsfeld/lyrics.htm) perhaps defines 3 epistemological classes:
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,
The ones we don't know
We don't know.’
—Feb. 12, 2002, Department of Defense news briefing
Known knowns,Logically there should be a 4th Rumsfeld class: the unknown knowns. And I think this class is especially important for data management for unfamiliar users.
Known unknowns, and
The problem is that in many research projects, there are too many people who “know too much”; with so much shared knowledge, much is un-documented. In OAIS terms, we are looking here at a small, tight Designated Community with a shared Knowledge Base, and consequently little need for Representation Information. In integrated science, and particularly environmental sciences, as the Community broadens and time extends, effectively the need for Representation Information increases. I’m using the terms very broadly here, and RepInfo can be interpreted here in many different ways. But the requirement is to make more explicit the tacit knowledge, the unknown knowns implicit in the data creation and acquisition process.
Interestingly, subsequent speakers seemed to pick up on the idea of making explicit the unknown knowns, so maybe the 4th Rumsfeld Class is here to stay in NERC!