All posts by Jon

Still here, folks

When we first designed the NSDL Registry, part of the requirements was that it be able to run in Lynx (seriously) and be usable without JavaScript in all browsers including all versions of IE. As you will probably have noticed, the world of web development has changed a bit in the last 8 years.

Lately it has come to our attention that the Open Metadata Registry looks a lot like abandonware. The reality is that we’re hard at work on a long-planned, often delayed, and absolutely necessary update.

Stay tuned.

Readable URIs

Over the years we’ve been engaged in a number of discussions in which the ‘readability’ of URIs was raised, either as an issue with non-readable URIs or as a requirement in new URI schemes.

At the Registry, we understand and are sensitive to the desire for human readability in URIs. However embedding a language-specific label in the URI identifying concepts in multilingual vocabularies has the side effect of locking the concept into the language of the creator. It also unnecessarily formalizes the particular spelling-variant of the language of the creator, ‘colour’ vs. ‘color’ for instance.

When creating the URIs for the RDA vocabularies we acceded to requests to make the URIs ‘readable’ specifically to make it easier for programmers to create software that could guess the URI from the prefLabel We have come to regret that decision as the vocabularies gained prefLabels in multiple languages. And it creates issues for people extending the vocabulary and adding concepts that have no prefLabel in the chosen language of the vocabulary creator.

That said, the case is much less clear for URIs identifying ‘things’, such as Classes and Properties, in RDFS and OWL, since these are less likely to have a need to be semantically ‘understood’ independent of their label and are less likely to be labeled and defined in multiple languages. In that case the semantics of the Class or Property is often best communicated by a language-specific, readable URI.

In the end I personally lean heavily toward non-readable identifiers because of the flexibility in altering the label in the future, especially in the fairly common case of someone wishing to change the label even though the semantics have not changed. This becomes much more problematic when the label applied to the thing at a particular point in time has been locked into the URI.

I’m not trying to start a non-readable URIs campaign, just pointing out that the Registry, in particular, is designed to support vocabulary development by groups of people, whose collective agreement on labeling things may change over the course of the development cycle, who are creating and maintaining multilingual vocabularies. Our non-literal-label URI default is designed to support the understanding we’ve developed of that environment over time.

SKOS updated for Vocabularies

Just a quick note that today we updated the version of SKOS that we provide for describing value vocabularies. This deprecates the properties that were removed from the final SKOS release and adds the many new ones. We’ve also restricted the non-mapping relation properties (skos:broader, skos:narrower, skos:related) to the ‘containing’ scheme while providing cross-scheme mapping for the mapping relations.

We don’t yet provide a useful interface for building collections, but that’s coming real soon now.

Oh, and we added a SPARQL endpoint.

Major update

The registry database was updated last week, in both the sandbox and the registry, to support history tracking. This is in preparation for finally enabling timeslice retrieval and versioning.We also made some significant changes to the site layout and css, so if things still look a little funky, try refreshing your browser — most browsers seem to be caching our css and not detecting the changed files.In the process, we broke search (you may not have even noticed), but it’s fixed now.

Mail is working again

If you tried to request your password and nothing happened, it’s because mail was broken on the server. Actually I had closed the port in the firewall a very long time ago and since a password request is the only thing that normally uses mail on the Registry, I hadn’t noticed.

Today I needed to register as a new user with this here blog (same server) and I didn’t get a password emailed to me! Oh, the sorrow.

It’s fixed now. Oh, the joy.