Organizing personal libraries of historical sources

Looking for organizing personal libraries of historical sources stored on one's computer, a presentation by Associate Professor Marti Hearst at U.C. Berkeley's School of Information as part of a course on search engine technology is useful.

Hierarchical faceted metadata represents knowledge so that it "can be understood well by many people when browsing rich collections of information."

Facets are sets of categories each of which describes different aspects of the objects in a collection. Facets can be hierarchical. Facets can also be mutually exclusive and exhaustive so that everything is guaranteed a unique description.

Examples in these Powerpoint lecture slides include organizing an art collection, a biographical site for Nobel Prize winners, and photos in photo collections such as Flickr.