Most useful knowledge is hidden

Thanks!

Tacit vs. explicit knowledge is a useful distinction, though I suspect it's incomplete.

Explicit knowledge is that which can be captured in text or speech, and which can be transmitted solely (or at least principally) by exposure to same. See also "book learning" or "book smarts".

Tacit knowledge must be practiced to acquire, and is not fully subsumed in text or speech. Classic examples would be the fine arts, music, or technical crafts.

Note that there's something of a continuum here, as there is knowledge for which transmission is improved when images, sounds, or video can be used, which are all "documents" or "texts" in a broader sense. Look at the immense number of teaching or training videos available online for examples of this. There's something about seeing the process which simply reading it does not convey. Text and speech are low-fidelity forms of information interchange when relating to real-world objects and actions, though they can work well in realms of ideas and intellect.

I see also a few other forms of knowledge.

There is a community knowledge in which the full knowledge of how to complete some task or process is not held by any one individual, but by an entire group, often acting largely independently of one another. This is manifested in numerous supply-chain and ad hoc community functions where outputs and services are delivered without any one central coordinating entity, whether by for-profit, non-profit, governmental, or volunteer efforts. The "knowledge" has no single repository.

I see communities of practice and cultures of practice as even broader levels of tacit knowledge.

Then there is environmental knowledge, which goes beyond simply human capabilities, and looks at the contributions of the natural ecosystem, animal, plant, geological, chemical, and physical, on which we all depend.

Relevant xkcd: <https://xkcd.com/2347/>