Nick Milton makes an interesting observation about "Capturing" tacit knowledge, referencing a discussion with Alan Knott of Parsons Brinckerhof:
... tacit knowledge is to some extent "captured" when the knowledge holder joins a network or a community of practice. Up to this point, the tacit knowledge is siloed; inaccessible. Once the person is connected into a network, their tacit knowledge is linked into a system.
I love this redefinition of what it means to "capture" knowledge. It goes along the lines of redefining knowledge management altogether. KM in its early days was about managing the evidence of knowledge work: document management, records management, etc. Or it was about managing access to knowledge through yellow pages and expert locators. This has shifted significantly where today knowledge management is about connecting people: connecting people to one another with the assumption that they will help each other and know how to ask.
I think this is the one area where KM still falls short. We provide the tools and forums, but people often don't know what to do once they have them. Does one simply ask questions? How does one take the next steps, once they have found a good nexus of knowledge? How do we solve problems together?
In other words: what is the system that we should put in place to ensure that people can make best use of the interconnections that Nick mentions above. That "best use" is likely defined by the people themselves and the goals of the network. Knowledge management has to include thinking along these lines.