In my current job, I'm constantly trying to figure out when the next thing I don't know that I don't know is going to bite me in the butt and cause me to have to rework my code. I've been working on a certain project for nearly a year, and still find out things that people have neglected to tell me, or are just considered tribal knowledge and everyone assumes you just "know", or is buried in the code (that I have to replicate in another language). It's not malicious, it's just how it is here, but it's incredibly frustrating.

So far the closest word I've found that sort of describes this situation is agnotology (the study of culturally induced ignorance, coined in 1995), but that's not exactly it.

What word adequately describes the situation where you don't know what you don't know?

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    I don't have a single word, but author David DeLong calls this "lost knowledge." amazon.com/Lost-Knowledge-Confronting-Threat-Workforce/dp/…. His book describes, for example, how NASA has a lot of information about landing a man on the moon, but would be unable to do so today because of the lost knowledge.
    – rajah9
    Oct 7, 2013 at 16:29
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    At my workplace we call it "Sacred Knowlegde", something that is not documented anywhere and is just known by several people who eventually leave the company :) Oct 7, 2013 at 16:34
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    Well at least you know there are things that you don't know about not knowing. Socrates would aprove.
    – Talia Ford
    Oct 7, 2013 at 16:39
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    Not a word, but I thought of Rome wasn't built in a day.
    – iterums
    Oct 7, 2013 at 17:55
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    I quite often use the term Unknown unknowns when discussing potential threats or opportunities to project development. This term was popularised (afaik) by Rumsfeld's poorly delivered (but surprisingly relevant) speech.
    – Bob Davies
    Oct 8, 2013 at 1:25

7 Answers 7


You might try adapting Rumsfeld's "(un)known (un)known" approach, although you would be best served by depoliticizing it in this situation. What you're dealing with are known unknowns, or certain bits of information that you know you do not know.

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    No - I don't know what the 26th brightest star in the constellation of Rigel is called. That's a known unknown (to me). A question I know has an answer, which answer I do not know. But OP is saying that he doesn't know what the next snarl-up will be (but he's confident there will be a near-inexhaustible supply). He's trying to anticipate potential problems - unknown unknowns. Oct 7, 2013 at 16:46
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    This is exactly correct, they're unknown unknowns (by me). Almost always the answer I get when I discover the next one (and I hope they're not inexhaustible, but it sure feels like it), is "oh, I thought I'd already told you that", or "oh, yeah, I forgot about that bit", or worst of all "I thought you knew that already"). They're known unknowns to those who have been using this particular database and it's quirks for years, but I'm totally new to it.
    – delliottg
    Oct 7, 2013 at 16:56
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    Right, but it still stands that OP now knows that there are more unknowns. "There are known unknowns, that is to say we know there's some things we do not know," yes? OP knows that there are issues he does not know (i.e. their presence is known), but he does not know what those issues are yet (i.e. their nature/solution is unknown). The issues are individually unknown unknowns (he doesn't know each issue, and therefore cannot know that he does not know them specifically), but collectively known unknowns (he knows that there are issues out there, but he doesn't know what they are). Lol.
    – userNaN
    Oct 7, 2013 at 17:28
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    ' "There are known unknowns, that is to say we know there's some things we do not know,"yes?' NO . Rumsfeld mentioned 'unknown unknowns' so he 'knew' there were some. But he didn't know what these questions / problems / factors might be. A known unknown is where the agent knows what the issue is but not the complete details (I know that Taurus (not Rigel, as I erroneously stated above) has more than 25 stars, so I can define the data I'm missing precisely - the designation of the 26th brightest. I know what to research.) Oct 7, 2013 at 23:11
  • This seems to be the best description of the problem, although I quite like "blindsided" as well in @jeffsahol's answer below.
    – delliottg
    Oct 10, 2013 at 15:42

A term that is becoming popular in the software company where I work is "technical debt", though I'm not sure it's really what you're looking for.

"Technical debt" refers to those imperfections left in a software product. This includes architectural flaws that there wasn't time to fix, detected and undetected bugs, badly written code, etc.

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    Yeah, technical debt is more of a known unknown. You know there are problems with the code, you've mitigated them, and pushed the eventual solutions into the backlog where they get bubbled to the surface as time & severity allow. This company is not a software house, they had never had code reviews till I got here, there is no test team, no such thing as user stories, scenarios, acceptance criteria, etc. However, they're very willing to learn, if at a glacial pace...
    – delliottg
    Oct 7, 2013 at 18:55

Once it happens, you have been blindsided:

To catch or take unawares, especially with harmful or detrimental results

So these unknown areas of ignorance are your blind side.

  • I like this term, and I've used it more than once when talking to my (very accommodating and understanding) manager, but it doesn't quite seem to catch the flavor of what I'm looking for. I know the problems exist, I know they're going to keep coming, I know I'm going to have to revise my code to accommodate whatever they are, so I don't feel so much blindsided as I am under informed. There's no spec to work from, no schema (I had to build one from gigabytes of data), just the directive to take that crappy server and emulate it with a proper server so the client never knows the difference.
    – delliottg
    Oct 7, 2013 at 17:08

As a student of industrial technology, I think the technical term for this is

chaos noun 2b : the inherent unpredictability in the behavior of a complex natural system (as the atmosphere, boiling water, or the beating heart)

If there was some way you could predict it, then it would have some pattern or dependence. Having no pattern or discernable relationships is by definition a chaotic environment.

Shewhart framed the problem in terms of assignable-cause and chance-cause variation and introduced the control chart as a tool for distinguishing between the two. Shewhart stressed that bringing a production process into a state of statistical control, where there is only chance-cause variation, and keeping it in control, is necessary to predict future output and to manage a process economically.

Wikipedia excerpt of Shewhart, Walter A.


I have struggled with trying to summarise that sentence as well, and have thought that maybe saying "Ignorant Unknowing", or variations thereof, might be a fix.


Anosognosia - Lack of awarenes

  • I don't believe this word describes the situation. It means more like unaware of a problem, than aware there are problems, just don't know what they are.
    – delliottg
    Aug 21, 2015 at 16:28

I proffer the word: undereducated.

Oxford Defined as poorly educated. AHD Defined as poorly or insufficiently educated.

As a rule, education reveals things you didn't realise that you didn't know.

Edit: A theory was developed which is referred to as the "Conscious Competence Learning Theory."

  • Stage 1 - 'unconscious incompetence' - Learners or trainees tend to begin here.
  • Stage 2 - 'conscious incompetence' - learner becomes self aware.
  • Stage 3 - 'conscious competence' - learner acquires skills.
  • Stage 4 - 'unconscious competence' - hopefully this is the final stage.

More on this theory is here.

  • A comment as to why the down-vote would be helpful to me. Oct 7, 2013 at 16:43
  • 'Twas not I, but you might have offended some fans of Socrates with the pejorative (Collins usage, which stipulates connotation) 'undereducated'. Oct 7, 2013 at 17:07
  • I didn't down vote, but I am certainly not under educated. Under informed in this particular instance? Certainly. Ignorant? Possibly, of all the bits & bobs necessary to make this work, but not for lack of trying. How do you know which questions to ask when you don't know the scope of the problem and when you try to define the scope, the owners of the problem don't remember all the fragile pieces, the workarounds, the hacks that went into keeping it running because it was poorly designed in the first place?
    – delliottg
    Oct 7, 2013 at 17:15
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    @delliottg Are you Dilbert in disguise? Oct 7, 2013 at 17:16
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    @Friendly Greasemonkey: according to the AHD definitions, 'undereducation' may be a clinical / neutral term (insufficiently educated [for the task in hand] – probably universally true to some degree) – or a denigratory term (poorly educated). Any usage without disambiguation can reasonably be expected to have at least a negative connotation. Oct 7, 2013 at 23:20

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