I am interested in type theory and proof theory. I have read a lot of papers and books that use the term "computational content" (For example: <https://scholar.google.com/scholar?hl=en&q=%22computational+content+of%22&btnG=&as_sdt=1%2C33&as_sdtp=>) and I have developed an intuitive sense of the meaning, but I have never seen the term formally defined.


Is anyone aware of a paper or book which defines this term?



What is the definition of computational content?
Let me respond to your comments to Bjorn and Matt's answers:


Let's say I have a sentence of the form $\forall x\exists y\theta(x, y)$, where "$\theta(x, y)$" is "simple" (say, only bounded quantifiers) - I'm not interested in how hard it is to evaluate $\theta(a, b)$ for a given $a, b$. Then a computational interpretation begins with *Skolemization*: we look at the sentence $$\exists F\forall x(\theta(x, F(x))).$$ We're interested in what sorts of $F$ work here.


One reasonable question to ask is, *Can such an $F$ be given by an algorithm?* This yields a distinction between "computably true" sentences and "not computably true" sentences.


But as you correctly observe, this is a very coarse distinction in many cases. We often care about the runtime of an algorithm, or its complexity in some other sense (e.g. space used). So we may ask: "Is there an $F$ which works *which is in $\mathcal{C}$*?" for some nice complexity class $\mathcal{C}$.


We may also be interested in *provable* correctness. Maybe there's a polynomial-time computable $F$, but *proving* that this $F$ works requires large cardinals :P. It would be quite reasonable to say that this is pretty bonkers. So now we're interested in the theories within which statements like "There is a polytime-computable solution" are *proved*.


And, finally, we may also run into the opposite problem: given two non-computably true sentences, we may want to argue that one is "more computably true" than the other. To do this we now need to *compare* noncomputable functions, e.g. via Turing reducibility. So we can also go to a "larger" context, and work there. (See e.g. [this paper](https://arxiv.org/abs/1408.2763), and also [reverse mathematics](https://en.wikipedia.org/wiki/Reverse_mathematics).)


All of these concerns - the complexity of Skolem functions, and the difficulty of proving such complexity results - are broadly part of one intuition: that our desire to prove a theorem does not stop only at determining its correctness. I would call all the nuances of a theorem, in this sense, its "computational content" - and since this is so broad, I would not hope for a formal definition of this term. (You could create one, but I think it would necessarily lose some of the aspects of the term. Not everything has to be formalized, and I say this as a formalist!)


