Relatively recently, UniProt (a protein sequence database) announced they were moving away from LSIDs (which are URNs) to URIs. The cons of LSIDs seem to be outweighing the pros. More generally, there seems to be much discussion as to what is more appropriate and what can and cannot be done with URIs vs URNs. And even some of LSIDs proponents are saying that using them at the moment is not a good idea.
The form of a URN is: urn:lsid:ubio.org:namebank:11815 which can be resolved using: http://lsid.tdwg.org/summary/urn:lsid:ubio.org:namebank:11815. A couple of IBM articles describe it in more detail: "Build a life sciences collaboration network with LSID" and "LSID best practices". Part of the problem seems to be that the LSID needs a resolving service, much like a web service, to return the data for a given LSID. The URI on the other hand can just use a bit of content negotiation to return either RDF data or human readable HTML. It's not a well known feature that a web client can tell a web server what data it can accept. So a Semantic Web client would say "give me RDF" and a normal web client says "give me HTML".
An alternative is using an existing standard, such as THTTP, which shows how to turn a URN into a URL by providing a REST based service. Where, requesting a URL for the urn "urn:foo:12345-54321" it becomes an HTTP request "GET /uri-res/N2L?urn:foo:12345-54321 HTTP/1.0". This is a bit like the biordf.org approach of "http://bio2rdf.org/namespace:id". Having de-referencable URIs is part of the Banff Manifesto.
Creating GUIDs is an interesting problem in a distributed environment. One of the other life science groups compared Handle, DOI, LSID and PURL (persistent URLs).
The mentioning of the Handle System brought back ideas from previous digital library work and using URNs to name RDF graphs (which I later to discovered wasn't entirely novel).
Showing posts with label uri. Show all posts
Showing posts with label uri. Show all posts
Wednesday, August 08, 2007
Friday, July 07, 2006
Identifying with the Web
URIs and the Myth of Resource Identity "Another way to put it is that the authoritative descriptive information that I publish licenses the use of my URI in certain models. This is analogous to publishing some interfaces for an object in an object oriented system. You can never be sure that I won't (monotonically) publish an additional interface at some point in the future, just as you cannot be sure I won't publish more descriptive information about me..."
"On the other hand, even if it is not possible to completely describe a resource, it may be possible to unambiguously identify that resource, in the sense of conveying what resource it is, as distinct from all other possible resources.
For example, if I provide descriptive information telling you that the URI http://t-d-b.org?http://dbooth.org/2005/dbooth/ identifies all-and-only the actual, living person with email address dbooth@hp.com as of 1-Jan-2005, that is sufficient to unambiguously identify me, distinct from all other possible resources."
"The ability to uniquely identify a resource -- in the sense of conveying the distinction between this resource and all other resources -- is important because it enables others to publish additional descriptive information about the resource, beyond what the URI owner provides. The Semantic Web is all about the network effect created by the use of URIs as universal identifiers. When a URI's resource is uniquely identified, it enables "anyone to say anything" about that resource[4].
"If a URI's resource is not uniquely identified -- if others must rely solely on authoritative descriptive information about that resource -- then those who wish to make statements about it run the risk that they may have guessed wrong about what resource the URI owner was intending to identify. This hampers others' ability to make statements about that resource, thus diminishing the value of that URI. This is analogous to connecting, to the telephone network, a telephone that nobody wants to call: it consumes resources without contributing anything to the network effect."
Via, URIs and the Myth of Resource Identity.
Related to, Why Different Things are the Same and Architecture of the World Wide Web, Volume One.
"On the other hand, even if it is not possible to completely describe a resource, it may be possible to unambiguously identify that resource, in the sense of conveying what resource it is, as distinct from all other possible resources.
For example, if I provide descriptive information telling you that the URI http://t-d-b.org?http://dbooth.org/2005/dbooth/ identifies all-and-only the actual, living person with email address dbooth@hp.com as of 1-Jan-2005, that is sufficient to unambiguously identify me, distinct from all other possible resources."
"The ability to uniquely identify a resource -- in the sense of conveying the distinction between this resource and all other resources -- is important because it enables others to publish additional descriptive information about the resource, beyond what the URI owner provides. The Semantic Web is all about the network effect created by the use of URIs as universal identifiers. When a URI's resource is uniquely identified, it enables "anyone to say anything" about that resource[4].
"If a URI's resource is not uniquely identified -- if others must rely solely on authoritative descriptive information about that resource -- then those who wish to make statements about it run the risk that they may have guessed wrong about what resource the URI owner was intending to identify. This hampers others' ability to make statements about that resource, thus diminishing the value of that URI. This is analogous to connecting, to the telephone network, a telephone that nobody wants to call: it consumes resources without contributing anything to the network effect."
Via, URIs and the Myth of Resource Identity.
Related to, Why Different Things are the Same and Architecture of the World Wide Web, Volume One.
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