Explicit knowledge can be documented in many forms. Documents, to be sure. Images. Tables. Movies. Audio recordings. Database queries. Plans written on napkins. Drawings. Such artifacts represent a process of drawing out, of memorializing tacit knowledge. They are very helpful in transferring such knowledge. Given the frailty of human memory and the relatively short life spans of us all, the ability to put aspects of tacit knowledge into permanent form is important to our well-being.

Explicit knowledge forms, of course, do have their limits. They are better at teaching us the "what" of knowledge than the "how". The problem is basically a structural one. Knowledge branches out in tree form -- based on individual frames of understanding. When using explicit knowledge tools, it is very awkward to determine how much detail of each branch to show, given that the reader will be faced with all of the material. In many cases, they are forced to learn all of it in order to understand some of it. In fact, however, they do not learn all of it, as the designer is really unable to address all issues due to the inflexibility of explicit tools. The bigger the document, the less available the knowledge housed within it.

Another way of describing the challenge of explicit knowledge is that it has a problem with context. Once you have made a choice, once a parameter has changed, once time has passed, you face a different situation. The new development may or may not be significant one, but it may change everything. The more an expert pours into the explanation of the difference, the more "off-putting" the resulting document can become. Certainly, such detail is important in explicit documents, but it does take its toll, particularly where time is short.