[Ref-Links] A missing piece: response protocols

[Eric Hellman <eric@hellman.net>]

One thing that has been largely unaddressed in the whole discussion of
reference linking has been the nitty gritty of how a linking database can
determine, in an automated way, whether a link is correct.

I'll cast this discussion in terms of DOI for argument's sake, but the
exact same issue is present in any cooperative linking system (one where
multiple entities are responsible for serving links), including S-Link-S
and PubRef LinkOut.

Right now, all that a verification system can do is check the HTTP response
codes for a URL. A "404 Not found" is obviously a bad link, but what about
"401 not authorized" ?

If the DOi resolves to a commerce, registration or authentication page, how
is a database to know whether the resource behind the page is really the
resource that was registered? What if the DOi gets redirected to a page
that has a normal response code, but says in english that the resource has
moved or is not available?

One approach to this problem is for servers to return some additional
response codes, in meta tags, XML or RDF, that give a machine enough
information to verify the correctness of the URL that it wants to check.

In addition, it is very helpful when verifying bibliographic links to have
redundant metadata to check against. A query to the DOI database based on
journal/volume/page could return a valid but incorrect DOI. It wouldn't be
hard to develop a way to validate bibliographic citations without giving
away the metadata. This would benefit everyone.

In developing the metadata scheme for S-Link-S, I threw in some vocabulary
for expressing that a request was valid. I've now removed it because I
decided that it didn't belong, and something more complete was needed.

Is any one interested in developing a proposal in this area?

Eric
Eric Hellman
Openly Informatics, Inc.
http://www.openly.com/           Tools for 21st Century Scholarly Publishing

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