tacit-knowledge

Tacit knowledge is know-how that lives in your hands and your practiced judgment — you can do it, but you cannot fully write it down or say it in words.

The procedural-knowledge literature says that know-how is often tacit: difficult to transfer by writing it down or verbalizing it, because it is formed by doing. The opposite is explicit knowledge — what you can write in a sentence. A checklist can capture a method's explicit skeleton (the questions to ask) but not its tacit flesh (the judgment that answers them). This is why a method can transfer as a checklist and still leave the new user without the expertise: the explicit part travels, the tacit part stays with the one who practiced.