> (and the reason to go metaphoric in the first place is to make the concept less abstract) I completely agree with you there. But I disagree that the unusual

> (and the reason to go metaphoric in the first place is to make the concept less abstract) I completely agree with you there. But I disagree that the unusual library example is more abstract. As a point of contrast, I gave an abstract account of technical debt for the purpose of comparison to the more concrete library metaphor (to show that the abstract account would be more difficult for many): > technical debt is about the up front time-cost of introducing new systems of organization to replace ad-hoc, unsystematic methods whose cost-effectiveness decreases as project complexity (to put it loosely) increases. A library with 25 books is not more abstract, though it is a hypothetical concrete thing [1]. If someone has difficulty with hypothetical concrete things, that could certainly make using metaphors with them more difficult—and I can see why you would add additional constraints onto what makes a good metaphor. In my personal experience, saying, "imagine a library, but with only 25 books, which is run by a single person," would be not asking too much of an audience. But I see your point that some may struggle with it. [1] There is a handy way of considering this distinction: becoming more abstract involves making some 'parameter,' which was fixed, free instead: so for instance a more abstract notion than any particular library is: a manager of a collection of objects which are loaned out to people for limited durations of time. In that example, we free the parameter 'book' so that it isn't set to anything specific. If we instead say, "a library but for CDs instead of books," it's equally concrete since we haven't freed any parameters, we just replaced one concrete value for another. That's what happened in the "library with 25 books" example, which is why I say it is not more abstract.