The NKOS Special Session at DC2005 was a stimulating session, filled with people who’d thought long and hard about the issues involved in knowledge management. The session, chaired by Traugott Koch (now of UKOLN), brought together enough people and ideas to make a whole afternoon go by very quickly.
Monthly Archives: September 2005
Returning from DC2005
Registries were a hot topic at last week’s Dublin Core 2005 Conference in Madrid, Spain. One highlight was the gathering of the registry-heads: the DCMI Registries Working Group meeting on Wednesday. Continue reading Returning from DC2005
Knowledge Organization Systems
There was an interesting discussion at lunch about SKOS and I finally had something click about the taxonomy of terms for ontologies. Yeah, yeah I know, but give me a second… It seems to me that it goes like this:
1. In the beginng was a controlled vocabulary, and it was good, but it was a flat list of terms.
2. A taxonomy is a single controlled vocabulary that contains an explicit hierarchy of terms that are related solely by their relative position in the hierarchy.
3. A thesaurus is composed of one or more controlled vocabularies and the relationship betwen the terms is expressed using a controlled vocabulary of ‘thesaural’ relationship concepts.
4. An ontology is composed of one or more controlled vocablaries and the relationship betwen the terms is expressed using relationship concepts that do not necessarily belong to any specific controlled vocabulary of concepts.
This may not be entirely correct, but it sure helped me make sense of that whole landscape.
Blogging the DC2005 Architecture WG Meeting
There was a discussion about the possibility of creating copies of the dc namespace elements in the dcterms namespace. Despite my personal strong support, Andy decided that there wasn’t a strong consensus for or against and that it might be best to table the suggestion until some of the other architecture ‘earthquakes’ subsided.
Domains and ranges…
* Domain is a class of resources that a property can be used to describe
* Range is the class of resources that are allowed as values of a property
* goal: making explicit what is currently implicit
dc:creator was the prime example in which the creating ‘entity’ is generally presumed to be the equivalent of the ‘name’ attribute of the more abstract creator entity. In other words a string such as “Jon Phipps” which is, according to the definition, incorrect. So what’s really at the URI that identifies dc:creator? Don’t worry, it’s an RDFism (I’m not yet a fan). Well, talk about a sticky wicket!
The 1.5 hour discussion that ensued finally devolved into a choice between explicitly defining range and domain attributes for the existing dc URIs, thus breaking any applications that used that element incorrectly, or creating an entirely new set of URIs for dc, thus permanently branching dc and leaving data rendered using the current URIs to stew in their own global incorrectness. Se ha tirado alguien de pedo? (pardon my spanish) Alistair suggested creating a new namespace for the new URIs and declaring that namespace to be a private playground, giving the architecture group and other early implementors some time to get dc’s RDFishness more fully baked. No conclusions had been reached by the end of the meeting but Andy was definitely starting to look a bit fried around the edges.
Tom said later that at the beginning of the discussion 30 people thought they understood what was being discussed, but as the discussion wore on, that became 10 people, and then 5, then 2, and finally one, who explained it to everyone, this explanation being understood by 10, and then after a bit maybe 30. Rinse, repeat.
The most often expressed reason for the whole exercise was to make dc more attractive to folks who refused to use it because it was too fuzzy. My humble opinion? Well, I’m so glad you asked… Go ahead and do the new URIs, clearly identify them as a draft spec that WILL change, don’t break the current URIs, change the definition of the new URIs as much as you want, but make them very public. It’s important to keep the needs of metadata providers distinct from the needs of metadata consumers.
If both providors and consumers operate only in the same domain, then how they cook their metadata doesn’t matter. But consumers of other people’s metadata will always have to deal with a wide variety of flavors indefinitely. There’s no way around this, no way to make their life easy — look at how many browsers still support HTML 1.0 and how many web pages must be written to work in Netscape 4 or IE 3. Consumers will just have to deal.
Providers (this includes the group that dc is concerned with attracting) on the other hand will appreciate the tightened spec, even if it’s unstable — look what happened with XQUERY (yes I know there’s a bunch of people really unhappy with how long that’s been in draft) — and will move toward it. Plus everyone’s RDF is not fully baked and trust me, they’re as used to dealing with a changing spec as the dc architecture folks would like them to be. And besides, some people like and find value in fuzzy (me for one). Just my $.02