Jurgen Appelo’s take on unknown unknowns needs a little more work:
It is important to understand that the unknown always depends on the observer. Some people already knew about black swans, but that didn’t make them any less surprising to those who had never seen them. My fellow board members already knew they wanted to leave their positions a good time before they shocked me with their announcements. […] Getting people together to share information and make joint decisions is the best way to deal with the unknown.
About “unknown unknowns”:
- If something will happen, but you don’t know “if” or “when”, it is a “known” unknown. Someone leaving your organization is a known unknown because you know employees do leave companies, but you don’t know when. You can put in possible scenarios and plan for them.
- “Unknown unknowns” are the events that you don’t even know about or you dismiss as highly improbable without thinking twice. For instance, 9/11. Yes, we have all heard of hijacking, but 4 planes hijacked at the same time bringing down 100-story buildings would have seemed like ridiculous fiction till it happened.
- Which means that you have no way of planning for it. You are totally blindsided when it happens. For known unknowns, you can list them and plan for them.
The mistake that people make is thinking that “unknown unknown” is equivalent to “something bad”. We know of many bad things that could happen to us and we can prepare for them. If you can list an example of “something bad”, that instantly makes it a “known” quantity. It is similar to the management principle that the very act of measuring changes what is being measured. Example: Measuring bug count dramatically reduces the bugs reported (and perhaps, actual bugs, though that is not a given).
What can you do about unknown unknowns? Nothing much really, except insurance. If something bad happens to you, you need to think of the worst possible effect and buy insurance to protect yourself. Unknown unknowns could also be large positive events (obscure relative dies and leaves millions to you). I don’t know if you need to even worry about that, but maybe you do.