While doing research for my two speaking engagements in November, I ran across a great article by Donna Slawsky on building a keyword library. The article discusses one of my favorite topics - aboutness in terms of identifying images - and also spells out clearly how and why to create a taxonomy for managing the keywords applied to digital assets.
The photo example supplied in the article and the findings displayed are accompanied by the astute observation that "people use different words to express similar ideas, concepts and even things."
This is the main reason to create a taxonomy. Consistency in tagging assets begets consistency in retrieval.
Finally, the topic is summarized with some tips on creating the taxonomy - whether to take on the work in house or outsource to a freelance thesaurus developer. "Work on a thesaurus is never complete."