Unknown unknowns

Interesting chat yesterday with Bill and Tamara about (among other stuff) "unknown unknowns" concept propelled by Donald Rumsfeld (taken from Slate compilation):

Reports that say that something hasn’t happened are always interesting to me, because as we know, 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

Represented on a 2x2 matrix, it goes like that:

Why do I blog this? the concept is pertinent to Knowledge Management (and hence discovery) because it's the dimension that we're looking for: it's often through serendipity that implications are created/dots can be connected. Rumsfeld is refetring to the unforeseen contingencies of situations. And this, whatever one might think of Mr. Rumsfeld; it shows the guy's background, very well oriented towards "Decision Theory".