Knowlegde is codified through a people-to-document approach. This approach allows people to search for and retrieve codified knowledge without having to contact the person who originally developed it. This opens up the possibility of achieving scale in knowledge reuse and thus of growing the business.
The personalization approach emphasizes the dialogue between individuals, brainstorm sessions, building networks of people. They do documents information, but the purpose is the ability to search for what people have knowledge about a certain thing, so you can contact hem.
Hansen et al.'s have found that successful companies use one of the strategy's and uses the other in a supportive role.