Thank you very much for your reply. Yes, I think your point is correct. I think I was arguing to use a tag-like (well I said faceted metadata) system instead of an ontology, but for this specific project I was more interested in having an ad hoc approach where people could add categories if nothing appropriate existed, and people could edit categories in a wiki-like manner. Well I didn't have that totally worked out for a large group, which is what I wanted to support, and certainly the del.icio.us way is very interesting.

I am curious about how useful tagging would be for both my original system (intended to focus solutions to sub-problems for use in helping earthquake survivors) and the PM knowledge base which certainly seems to have some solid categories.

But as I think about it now it does seem that the key here is that a plurality of people will be involved in an editing or knowledge focusing process, and since they share the same vision of focusing knowledge and using perl, then the tags they select will be relatively focused as well. In which case a separate set of "narrative threads" would then need to be added by people, for example in PM they might indicate a favored order in which to view a set of nodes for use as an introductory text. In my ad hoc disaster aid system I think it also needs an engine or a human editor who drives forward the overarching requirement that we find a concrete answer to a problem within a given time frame (like who will bring what, where, for someone to drive to the disaster site). There can be all kinds of side discussions going on but the main thing I wanted was to solve a problem.

I had a vision of a very simple user interface with a small text entry box and a pull-down menu with subject names to select from, or you could add your own subject (or tag I guess). If you start up a new project to solve a different problem, you would have a different set of starting tags. I thought I would have a person periodically reorganizing things and reducing the number of tags as much as possible, or adding new ones (developing themes) to keep everybody headed toward resolution of the problem in a finite amount of time. This is not quite as important for PM perhaps.

Well, thank you for a really interesting note, it has gotten me thinking in new directions since I had not realized everything del.icio.us could do until now, and it seems to lead the way toward better architectures.

In the PM KB, it would seem then that you could derive a lot of information (metadata) from nodes (if you had access to the database) like who posted what when, how many votes the thread and each answering node got, and linked nodes and sites, which could provide a lot of initial tagging information.

I think the most interesting thing here is that user XP, which has been said to be useless, and votes per node, may in fact be the most useful tools we have to determine who our most influential editors are and what threads and nodes have served monks the best. Perhaps we already have sorting by votes built in to Super Search or something else? Best nodes this month seems also to be a good source of informaiton.

To get farther on this I think we need a corpus to look at, in other words start messing with WWW::Mechanize or something else to examine PM in these terms, or obtain readonly access to the database.

So thanks again and looking forward to hearing more from you if you have time. Yes, I agree with you about ontologies but would like to experiment with adding structure (albeit changing and minimal) to tags, and to add tags that have meaning in terms of an overall objective (i.e. solving a problem, or explaining perl and good solutions well). Great!