At a Pentagon press briefing in 2002, then U.S. Secretary of Defense Donald Rumsfeld was asked about reports suggesting there might not be evidence of the Iraqi government seeking weapons of mass destruction.  Politics aside, his answer would ultimately define his legacy and become the namesake of his autobiography.  His edited response to the reporter included the following language:

“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.  […] it is the latter category that tends to be the difficult ones.”

What Rumsfeld was describing were different classifications of risk.  I view these three categories through a simplified perspective as follows:

• Known Knowns: Facts we understand
• Known Unknowns: Variables
• Unknown Unknowns: Unimaginable uncertainties

Known Knowns

Known knowns are things we are aware of or facts we fully comprehend.  At a 2006 post-game press conference, then head football coach of the Arizona Cardinals, Dennis Green, famously ranted:

“They are what we thought they were.”

after losing to the Chicago Bears.  The exclamation was in response to a question about the six turnovers his team gave up and whether his team was prepared for their opponent.  He believed the Bears were Known Knowns. Yet, sometimes, even when there are Known Knowns, you lack the intelligence, ability, correct tactics, or resources to be successful.  It is possible to have all of the relevant facts, completely understand that data, yet still not be able to accomplish a task, win an argument (or a football game), or use the information to your advantage.  Knowing all the knowns about a circumstance doesn’t always equate to success or a positive outcome.  You still need to execute.

Unknown Knowns

There is also a fourth piece to this hierarchy of risk classification that Rumsfeld did not mention: the Unknown Knowns.  These are facts that we know but may have forgotten, take for granted, or categorize as intuition.  Maybe they are facts that we know exist, but are not part of our consciousness.  For example, I know all 50 U.S. state capitals, but I could not recite them at this exact moment if queried.  In business and life, these may be facts that we learned at one time and are known, but we are just not consciously aware of them.  It is also possible that we know certain facts, but purposely do not give them consideration (i.e. confirmation bias).

Known Unknowns

Known Unknowns are variables or risks we know exist, but whose effects cannot be precisely determined. In risk mitigation, we focus on these Known Unknowns, trying to quantify the possibility of an event occurring or having an impact.  I often use a risk analysis tool when making more complex decisions.  First, I gather all the facts available by doing as much research as possible.  Most critical is to try and remove any bias from the gathered data or at least to be aware of its existence.  Next, I evaluate the probability of an event occurring, its potential impact, and my ability to detect it.  With effort, Known Unknowns can be measured to the point where logical, risk-based decisions can be made.

Unknown Unknowns

The more we educate ourselves on a particular subject, one would think that we convert unimaginable uncertainties into quantified risks (i.e., convert Unknown Unknowns into Known Unknowns).  However, there will be instances where the knowledge does not exist.  Maybe it is something that has never occurred before, or there is no record of it.  Sometimes, there is simply no precedent or reason to believe that something could even be possible.

Regardless of whether we know or don’t know, there has never been more data available to us right at our fingertips.  In all aspects of work and life, ideally, we make informed choices based on unbiased truths.  We predict outcomes based on the facts at hand (Known Knowns) and an evaluation of the risks (Known Unknowns), while often ignoring information that is inconsequential or does not support our desired result (Unknown Knowns).  However, there will always be Unknown Unknowns.  Those are the events, scenarios, risks, hazards, etc., that we could not possibly have imagined or even known existed.  And, as Donald Rumsfeld theorized, these Unknown Unknowns can be the most difficult to deal with.