Tacit knowledge
Tacit knowledge is what a person knows but cannot easily write down: judgment, pattern recognition, feel. It is built from years of accumulated cases and shows up in decisions and conversation, not in documents. The philosopher Michael Polanyi summarized it as "we know more than we can tell."
What is tacit knowledge?
Ask a veteran technician how he knew the bearing was failing and he will say "it sounded wrong." That answer is real knowledge — thousands of hours of listening compressed into instant recognition — but it resists documentation, because the knower himself cannot fully articulate the rule he is applying.
Not to be confused with explicit knowledge, which is everything that can be and has been codified: procedures, specifications, manuals. Most knowledge-retention projects capture explicit knowledge and stop — precisely because tacit knowledge is the hard part.
Why it matters for SME continuity
In an SME, the difference between a competent successor and a struggling one is almost entirely tacit: reading a client, sensing when a deviation matters, knowing which corner may be cut. That is also the knowledge with no backup anywhere. When surveys of departing experts talk about "lost knowledge," the tacit share is the loss that hurts.
Tacit knowledge inside MentX
Tacit knowledge surfaces in use — in decisions, corrections and explanations. That is why MentX captures from meetings, where tacit knowledge is exercised daily, and adds a guided intake track that asks the questions that make the implicit explicit: not "what is the procedure?" but "walk me through the last time you overruled it." See how MentX works.