Knowledge transmission.

“The point here is that the crucial knowledge in any innovative industry is not standardized information, routine patterns or the public knowledge of science.  It is also often not the kind of data that can be obtained through quantitative market research involving the analysis of secondary data or statistical survey research, nor from qualitative methods such as focus groups and interviews.  What is really useful is what is new, what are the latest changes and the specialized know-how that individuals have acquired through practice and mistakes.

Pierre Desrochers, “Geographical proximity and the transmission of tacit knowledge,” The Review of Austrian Economics