It perhaps was a mistake to try and cover Thing 8 on a Friday afternoon. I've quickly read Clay Shirky's essay, ontology is overrated but I was struggling to keep going! (more coffee is needed I think).
I can see some of the problems of a static system, whereby one person, or a group of people decide how to classify, or categorise an item (and I agree that with the web one can have a multiplicity of links to the same item), but I still feel that at some stage whichever system you use, it has to come down to "best guess" on the part of the searcher. An organic system whereby others can add tags may increase the success rate, but does not guarantee that the searcher will choose a label someone has given it. Similarly a system which searches all the words in an article, could cover a greater range of possible search terms, but cannot help if that term is not contained within the article...even though the reader could tell that that was what it was about.
Time I think to try and put some more tags on my previous entries...and refill my mug before I re-read the article.