The Rhetorical Presence of Tacit Knowledge

In defining tacit knowledge, Polanyi distinguishes between formal, scientific rules and procedural rules. Thus, he notes, the formal dynamics of balance on a bicycle do not comprise the rules of riding. To the extent that experts can articulate explicit rules (e.g., lean into curves), knowledge moves from the domain of the tacit into the realm of scientific expertise. 

Collins builds upon Polanyi s notion of tacit knowledge to explain why procedural instructions do not contain sufficient information to enable apprentices to replicate their operation in a new lab. For Collins, tacit knowledge is cultural knowledge that is not made explicit in rules and procedures. In the case of the tea laser, for example, he describes how some apprentice 

Like the concept of tacit knowledge, pit sense describes information that is not articulated in written rules and procedures. There are, however, important differences. 

the term tacit implies silence. The term describes a set of understandings and behaviors that are coordinated and understood in particular social settings prior to their articulation in language. Indeed the term depends upon a notion that certain things may be quietly understood, but not spoken, as a function of group activity. Pit sense, on the other hand, is not understood until it is felt or perceived by individuals in particular material sites. Pit sense may be articulated as a set of commonplace, but the activity of sensation resides in the individual knower who feels or senses changes in material conditions. 

Second, Collins s notion of the tacit presumes that apprentices will replicate a previously working artifact. New lasers are said to fail if they fail to work in similar, predictable, and controlled laboratory environments. In the mines, however, apprentices may replicate previous procedures, follow fully articulated rules and procedures, and still fail because new situations and environments change the conditions that enabled previous models to succeed. 

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