I don't have exact numbers (I will look into this next week) but multiple ISBNs and ISBN reuse happens enough to give us a headache. 


Sent from my iPad

On May 17, 2013, at 0:56, "Ford, Kevin" <[log in to unmask]> wrote:

> These are all good things to think about.  But in re-reading your email, with the idea of commenting on each, I am struck by the specificity.  It's not that the specifity is a bad thing, by any measure, but that, ultimately, we are trying to establish some form of useful guidelines that will accommodate a very significant percentage of cases.  I'm not saying what you've identified are edge cases, but I do wonder how common they really are.  That said, what we can figure out now and reasonably address, let's look at.  Is there any way to quantify, for example, how often publishers actually reuse ISBNs in different editions (is that even tecnically permitted?)?
> In the end, we must all accept that it is not going to be perfect.  We want it to be but, as you and others have very rightly pointed out, bibliographic data can be messy.  There is, quite simply, nothing "safe" on which to unambiguously identify instances of works in MARC records.  The "splitting" will be some complicated calculus that takes into account ISBNs, bindings, and publication information.
> Yours,
> Kevin
>> -----Original Message-----
>> From: Bibliographic Framework Transition Initiative Forum
>> [mailto:[log in to unmask]] On Behalf Of J. McRee Elrod
>> Sent: Saturday, May 11, 2013 9:44 PM
>> To: [log in to unmask]
>> Subject: [BIBFRAME] What's an instance?
>> I tend to think of a Bibframe instance as an edition, but the Bibframe
>> instance seems to be something different, mainly in envisioning more
>> than one instance per edition, but occasionally more than one edition
>> per instance, using ISBN as the determining factor.
>> Often different bindings of copies of an edition have separate ISBNs,
>> but Bibframe says one instance per ISBN.  Since binding is normally not
>> mentioned in description (using "description" in its usual sense, not
>> to mean abstract or summary), how would these instance descriptions
>> differ from each other for the trade, library, deluxe, paperback
>> bindings?  One could have four Bibframe instances for one
>> AACR2 or RDA edition.
>> Often editions are published simultaneously by two or more publishers,
>> but Bibframe says an instance can only have one publisher.  Sometimes
>> these simultaneous publications have both or more publishers given in
>> the resource.  If both or more publishers appear, surely both or more
>> should be included in one instance description, even if each publisher
>> assigns its own ISBN?  Each ISBN describes the same resource; the only
>> difference is who sells it.   An instance description with one
>> publisher and one ISBN would not match any existing bibliographic item,
>> each item having more than one.
>> Occasionally publishers repeat an ISBN in difference editions.  Are
>> these two dr more editions to be one instance?  Which edition would be
>> described?  How does one handle both in the same collection with only
>> one instance description?  Rarely the same ISBN can appear in editions
>> of different works.
>> ISBN is not a safe litmus for determining editions (instances).
>> How do yearbooks or multivolume sets, with an ISSN for the serial, an
>> ISBN for the set, but individual ISBNs for the serial and set volumes,
>> fit into this?  (Utlas had 021 for analytical ISBNs of volumes within a
>> serial or set, a feature we still miss.)  While for ebrary, we must
>> create a record for each volume of a mutlivolume set or a serial,
>> because they can have only one 856$url per record, that is not
>> something we would like to do for all.  It would clutter up catalogues.
>> BTW, can an instance record have multiple PDF URLs?
>> If these volumes with their own ISBNs are separate instances, are each
>> instances of a separate work, or are all volumes instances of a single
>> set or serial work?  Instance records for these volumes would seem to
>> have more in common with MARC item records, than AACR2/RDA MARC
>> manifestation records.
>> The Bibframe provisions seem to me not to accord with messy
>> bibliographic reality.
>>   __       __   J. McRee (Mac) Elrod ([log in to unmask])
>>  {__  |   /     Special Libraries Cataloguing   HTTP://
>>  ___} |__ \__________________________________________________________