What are unknown unknowns? Definition and examples
Unknown unknowns are future outcomes, events, circumstances, or consequences that we cannot predict. We cannot plan for them either. We don’t even know when and where to search for them.
Unknown unknowns is a common term in strategic planning and project management. Project management involves planning, organizing, and managing many things, including a team to see through a project’s completion. Strategic planning is a company’s or organization’s process of defining its strategy.
BusinessDictionary.com has the following meaning of the term:
“Future circumstances, events, or outcomes that are impossible to predict, plan for, or even know where or when to look for them.”
Unknown unknowns – other knowns
Including unknown unknowns, four terms relate to the words ‘known’ or ‘unknown.’
Known knowns
This term refers to things that we are certain about, i.e., we know. For example, the US Pentagon knows how many American troops there are in the Middle East.

Known unknowns
Known unknowns refers to things we know exist, but we do not have all the information. We might not know, for example, how many of them there are.
For example, we know there are terrorists in the United States, United Kingdom, and France. However, we do not know how many there are. The number of terrorists in those countries is a known unknown.
Unknown unknowns
We know there are terrorists in our country (known known), but we do not know how many (known unknown).
We suspect they plan to do something in the future, such as set off a bomb or poison our water supply. However, we do not know what they will do, i.e., we have no idea. If they do something, we haven’t a clue when it will be. It is an unknown unknown. We are unaware of any terrorist plan. Put simply; we know nothing.
Unknown unknowns – Donald Rumsfeld
Donald Rumsfeld was US Secretary of Defense from 2001 to 2006. A journalist asked him a question regarding the lack of evidence linking Iraq’s government with the supply of weapons of mass destruction to terrorist groups. This was his answer:
“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. And if one looks throughout the history of our country and other free countries, it is the latter category that tend to be the difficult ones.”
Video – unknown unknowns
This CNN video shows Donald Rumsfeld using the terms known unknown, unknown unknown, etc.