Is there a word for the phrase "I don't know what I don't know"?

Solution 1:

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.

Solution 2:

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.

Solution 3:

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.

Solution 4:

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.