BUT here is the key thing which the 80-20 rule leaves out–EVEN if it is true–THE QUESTION IS: Not whether this large swath of informal learning is there, BUT (1) whether it is modifiable, (2) whether WE can actually modify it, (3) whether it is cost-effective to modify it, (4) AND whether modifying it produces benefits that outweigh the costs.

For me, in the workplace informal learning will almost always be guided (essentially by definition) by the mission and objectives people are working on (on Project X and Project Y and Project Z, or in the course of meeting daily accountabilities). People wonder about things relevant to what they are working on, they search for info and knowledge about what they are working on, they stumble upon and exchange useful info / knowledge, in the course of browsing, reading, thinking, chatting, exchanging.

I think (essentially, again by definition) that what people 'upload' informally then must be modified and modifiable as it comes into use. As to cost-effectiveness, it seems impossible to force people to focus all 480 minutes of an 8 hour day on defined tasks or problems, and it seems to me that what hey acquire / learn informally can't easily be related to costs as it (the informal learning) is just a natural part of what people do when they are ingesting, processing (sometimes) outputting information and knowledge relevant to issues and problems set out in their work agenda.

As an example, I'm thinking that the development of the "rules of thumb" in many areas of work activity is usually arrived at through 'informal' learning, about works best ... no ? Benefit, or burden ?