Lisa's Notebook

Writing Exercises by Lisa McNulty.

Unknown Knowns

The concept of unknown unknowns is something that I will come back to in the last section of my Sherlock series, but for now I’m just going to give it a brief spell in the spotlight by itself, and introduce a related concept of my own: ‘unknown knowns’.

The phrase ‘unknown unknowns’ comes from a response that Donald Rumsfeld gave to a question put to him at a US Department of Defence news briefing. He was asked about the lack of evidence linking the Iraqi government with the supply of weapons of mass destruction to terrorist groups. He said:

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.

Now setting aside the obvious weaselling, this is actually a really useful concept. There is one obvious missing piece, though, so let’s set it out below in a way useful to an epistemologist rather than a politician:

  • Known Knowns: You know what the question is, and you know what the answer is. (Hurrah).

  • Unknown Knowns: You know the answer, but you don’t know what the question is - or perhaps you do, but you don’t realise that the question connects to the answer. (This is the one Rumsfield leaves out, and I’ll write more about it in a minute.)

  • Known Unknowns: You have a question, and you don’t know what the answer is. (Go and read some things).

  • Unknown Unknowns: The question hasn’t occurred to you yet. As and when it does, you don’t have an answer available. (You might be aware this is happening, though. You know when someone explains a new concept to you and then asks if you have any questions; and you haven’t understood enough to formulate questions in the first place? That.)

To unpack my addition a little more: when you have a ‘known known’,: a question occurs to you and you remember the answer; a problem arises and you have the solution to hand. Your filing system is working. By contrast, when you have an ‘unknown known’, you have a poor filing system. You have information, or a skill, and a question or problem arises, which your information or skill could be used to solve. So in a sense you do know the solution to your problem. The trouble is you don’t know that it is the solution to your problem, because you haven’t used it in that particular context before. You haven’t made the connection. (This is why John Locke refers to knowledge as ‘connections between ideas’: just having ideas isn’t enough).

So for example, we might imagine an accomplished short story writer, who is stumped when writing an academic essay, either because they don’t ‘get’ the extent to which the skill-sets overlap, or because they are having trouble transferring their skills over to another area. Or someone who learns about two historical figures in different contexts, and only months or years later realises that they were contemporaries.

The ‘tip of the tongue’ phenomenon, where we definitely do remember the name just give me a second argh…. perhaps counts as an unknown known, but that’s more of a mere failure of memory, whilst I’m thinking of a failure in the way our ideas are organised.

We can also think of how organisations have this problem. For example, at my university one member of the philosophy department has published in the area of radical pedagogy; but until recently no-one in the education department knew this, which may have prevented some possible collaborations. At Dave’s previous company, one department needed an expert in the programming language R, didn’t have one, and didn’t know that the company did employ an R expert, but in another department. Only a chance conversation led to a useful collaboration; a searchable database would have solved the problem.

Unknown unknowns are indeed a tricky one. But often that situation is solvable by (a) recognising that you are out of your depth, and (b) finding someone who isn’t, by which I mean someone who is able to ask the right questions, rather than necessarily has the right answers immediately to hand.

Unknown knowns are a structural problem which can make the ‘unknown unknowns’ situation far worse, since (a) you may think you’re out of your depth when you aren’t, because you haven’t transferred the relevant skill set over to a new context, which is something of waste and (b) you may not have a clue who to ask for help, even though an expert is actually available within your organisation.

At the individual level, interdisciplinary approaches to learning can help minimise unknown knowns; at the organisational level, it requires ‘bridges’ between departments, and a corresponding respect for generalists. That way, even when you don’t know what you don’t know, you will hopefully know someone who does.


If you'd like to hear about my upcoming courses and events, like "How Not to Think Like Sherlock Holmes" or "The yet to be named Philosophy course based on Doctor Who." please sign up to my mailing list and I will very very occasionally send you information about these things.