I have been poking around in the Life Sciences Identifier (LSID) spec in recent days, and in fact a few of the die-hard semgrail (semantic web discussion group) folks met to discuss it recently.
At one point in the spec, the authors reprise LSID functional requirements with reference to URN requirements (LSIDs are registered as a URN sub-namespace). The laundry list includes both:
- Global scope
- Global uniqueness
I stumbled at this distinction in my first reading. Global uniqueness is part of identifier canon law, but also trivial to achieve in today’s distributed networking environment. We know it is foundational, but we get it for free as part of DNS network addressing.
But what about global scope? My first reaction was to think that they had merely parroted something from the URN specs and it had no direct implications for the functionality of LSIDs.
Further reflection occasioned an Aha! moment, however. Global scoping is not really an attribute of an identifier, but rather part of a service environment that comes into play when we deploy and propagate them. My modest flash of insight on this is born of my thinking about identifiers having to do with WorldCat.org. If we are as a community to increase the value of our links (that is, links to library-held materials), we need to agree on standard identifiers that are recognized and universally actionable (global scope of recognition).
The following identifiers are all valid within WorldCat:
Inspection tells us that 3 of the 4 are transactional identifiers and are thus less likely to be persistent. The last is an OCLC-number-based URL, which has, naturally enough, assumed the moniker of permalink in WorldCat. That’s the one to use. (It needs to be made more prominent in Worldcat. Don’t make me click to get it… it should be in bold at the head of every record presentation)
Permalink is a good name here, but it is also misleading in that people use the term rather indiscriminately. For example, this blog entry has a permalink as well, but lets face it, its persistence extends only as far as the business case that supports it (that is, until I stop paying my annual fee to Typepad or Typepad goes out of business). In the case of a WorldCat permalink, it is a reasonable bet that they will be useful as long as there is a globally-scoped bibliographic database.
Which brings me back to the point of this entry. One of the virtues of having the entire Worldcat database available to the Internet Commons is that we have a stable identifier that is globally scoped and inclusive of what increasingly rounds to the world’s library assets (yes, I’m over reaching, but a bibliographic utility’s reach should exceed its grasp, or what’s a WorldCat for?)
If I use an identifier bound to a local library system or any locally-scoped system, then I’ve done little to reduce barriers to more effective global access. A record identifier for a given asset in the UW system is probably different than that in, say, Ohiolink. An identifier in WorldCat will identify a given asset anywhere, and may be used for direct access within locally-scoped systems as well, if the systems are designed with global scoping in mind.
This doesn’t happen automatically, of course… system designers have to recognize and exploit the global scope of a given identifier. This is the nature of network value – the more something is used for a given network purpose, the more valuable it becomes.
The library community benefits from a public, globally-scoped identifier such as WorldCat provides for the first time. It should be the identifier of first choice in library systems.
Image: Early morning view of the 520 bridge from the Union Bay Natural Area on Lake Washington.