In response to:
Kwasnik, Barbara H.. (1999) “The role of classification in knowledge representation and discovery.” Library Trends 48(1): 22-47.
Hunter, Eric. Classificaton made simple. Chapters 2 and 3.
The a priori requirement of hierarchies and trees contrasts with tagging, and highlights one of the advantages of tagging that I have been considering recently. Time is an important aspect of any organization system, and for a while I had been seeing the issue one-sidedly. User-generated tags are more likely to suffer a degradation in usefulness over time as the trends in assigning keywords may change. As stricter, authority-controlled classification, like Library of Congress Subject Headings, may serve better for recall since the keys to access are consistently applied. However, with may of the things that tags are used to organize (frequently, emerging technology), there isn’t sufficient knowledge before hand or thought on the subject is changing to rapidly to create a hierarchical classification. Tagging serves as an interim measure, making blog posts and the like retrievable in the short-term. LCSH is effective once a subject has made it to printed books.