Be careful though, please don't send an rft_id ISSN identifier for an
_article level_ metadata package. OCLC does this. It's wrong, as the
ISSN does not serve as an identifeir for the _article_ cited, but rather
for the journal it's in. Until I figured out what was going on, this
caused some bugs in Umlaut.
It _would_ be nice to send multiple ISSNs even for an article-level
citation. Let's say the generator of the OpenURL happens to know that
there are several variant ISSNs for the publication, that identify
differnet manifestations, but any of which are valid for the given
article citation. It would be helpful for the generator to send them all
along, in case the link resolver knows about some but not all of them,
to increase the chances that the link resolver will properly 'recognize'
the citation.
But, it unfortunately can't be done. It's not the end of the world to
realize that OpenURL isn't perfect (what is? By trying you learn from
your experience to do better next time), but I'm unconvinced that this
is actually desirable in any way instead of an oversight. One thing I
think I feel like we've learned from many of our community's recent
metadata initiatives is the importance of creating standards in such a
way that they can be further developed and/or extended in a backwards
compatible way. Ie, an OpenURL 1.1 or something, that was backwards
comptable so it could be sent to resolvers that knew no more than 1.0
without problems. This has to do with both the design of the
structure/syntax of the metadata, as well as the design of the
_processes_ of maintenance, to make this kind of extension and
development not too cumbersome socially.
Jonathan
Karen Coyle wrote:
Ah, you're referring to rft_id, and I was looking at the ISBN element in
the KEV Book format. So using rft_id would work.
The reason for multiple ISBNs is that many MARC records have ISBNs for
the hard copy and the paperback. Without going through some gyrations
you don't know which is which, although for purposes like ILL either is
valid. There are also multi-volume works that each get an ISBN.
Like other FRBR levels manifestation has a fairly wide range of
ambiguity. A book simultaneously published in two countries... is that
one manifestation or two? What if they each get a separate ISBN? A
hardback and trade paperback that come out at the same time, where the
only difference is the cover... and the ISBN?
Although I often use the shortcut of ISBN = manifestation the fact of
it is that ISBNs are publisher inventory and sales numbers and are used
in ways that are convenient for publishers. They also get mis-assigned
frequently, as some tests being run on bib data at the Open Library are
showing.
kc
Ross Singer wrote:
Actually, this:
http://alcme.oclc.org/openurl/servlet/OAIHandler/extension?verb=GetMetadatametadataPrefix=mtxidentifier=info:ofi/fmt:kev:mtx:ctx
indicates that multiple rft_ids *are* valid, and, in fact, would have
to be, since you could very easily have a DOI and a PMID and, say, a
SICI.
I have no idea what any resolver would do with this bundle of ISBNs,
of course. It also seems somewhat contrary to the intention of the
Book metadata format, since I think it's (in my murky view of FRBR-y
terms) trying to define a manifestation rather than the expression
level that Bill is trying to use it for. I could be weaving in my own
interpretations and biases there.
An alternative would be use by-reference context objects and then make
the context objects available as XML. You could have multiple context
object available in one XML document this way. A combination of
COinS/unAPI could make something like this possible.
-Ross.
On Feb 18, 2008 6:53 PM, Karen Coyle [EMAIL PROTECTED] wrote:
Actually, the max occurrence of ALL of the KEV keys is 1 except for
au
(which is unlimited). I remember discussions in which we acknowledged
that one key NE one value, eg you could input multiple values if your
recipients were in agreements (a poor excuse, I know). Thus:
isbn:;isbn:. My only memory for why max=1 for all of these is
that it has to do with the fact that there is no structure or
dependency
in KEV, so an OpenURL with keys
rft.au=nnnrft.title=tttrft.au=rft.title=
isn't interpretable in terms of what authors go with what titles. Why
the exception for au but for no other fields? My memory fails me here.
Undoubtedly it made sense at the time.
kc
Jay Luker wrote:
Hi William,
According to the book KEV format (defined here:
ttp://tinyurl.com/2psmkq) the max occurrence of the isbn key is 1. I'm
assuming that by extension that means that the rft.m-key (i.e.,
rft.isbn) form is also limited to one occurrence. So specifying
multiple ISBNs that way is a no go.
You can however specify multiple referent identifiers. From the KEV
Context Object format matrix (http://tinyurl.com/2r5hsc): Multiple
instances of rft_id do not indicate multiple Referents, but rather
multiple ways to identify a single Referent
So
