Tacit's software, when installed in an enterprise, interacts with the e-mail system on every employee's desk and "learns" their expertise. No, it is not LinkedIn, where all individuals need to feed in their resumes and thereby "announce" their expertise. Tacit's artificial intelligence algorithms work in the background, reading all your e-mail exchanges, noting who you correspond with, how often and on what topics, and in this way, it creates a personalized profile of your areas of knowledge. Tacit's software includes privacy controls, so no one can access your profile without your permission.
Thieme Hennis on 12 Jun 08Yahoo! employee describes and defines criteria and algorithms for a collaborative tag system: Since tags are created by individual users in a free form, one important problem facing tagging is to identify most appropriate tags, while eliminating noise and spam. For this purpose, we define a set of general criteria for a good tagging system. These criteria include high coverage of multiple facets to ensure good recall, least effort to reduce the cost involved in browsing, and high popularity to ensure tag quality. We propose a collaborative tag suggestion algorithm using these criteria to spot high-quality tags.