Knowable unknown

The Devil’s Advocate™ →Go uptown There are six types of known. The Rumsfeld three: Known knowns: Things you do know you know; Known unknowns: Things you do know you don’t know; Unknown unknowns: Things you don’t know you don’t know; And the Jolly Contrarian three: Unknown knowns: Things you don’t know you do know. Not officially known: Things you know but the general public can’t prove. Knowable unknowns: Things you don’t know, but think you do know, for the time being, because computers. In which the curmudgeonly old sod puts the world to rights. Index — Click ᐅ to expand: The Devil’s Advocate Tell me more Sign up for our newsletter — or just get in touch: for ½ a weekly 🍺 you get to consult JC. Ask about it here.

Knowable unknown
/ˈnəʊəbᵊl ʌnˈnəʊn/ (also “constructive known”) (n.)
Hailing not from Donald Rumsfeld’s famous taxonomy, but the JC’s private one, a knowable unknown is something you don’t know, and can’t know, but believe you can as good as know, just as long as you have enough data, clever enough algorithms and a suitable array of industrial-grade reality distortion fields and bullshit detector defeat devices installed around you.

Such as that “options will behave as predicted by the Black-Scholes option pricing model”.

The problem with knowable unknowns is that they are irritatingly time-bound, and tend to be knowable at all the times where you don’t really need to know them, but then become suddenly impenetrably unknowable just when your pants are down.

Victims of expiring knowable unknowns include Long-Term Capital Management in 1998, the entire financial services industry in 2008,

See also

• System redundancy
• Unknowns