I had that question, and I'll add another one or three. :)

Both Shlomo's and Roy's data show records with 4 ISBNs within the top 4 places. For Shlomo, 4 ISBNs is in 4th; records with 4 ISBNs are in third for OCLC (comfortably ahead of those records with 1 ISBN). How many of those records with 4 ISBNs represent coupled ISBN-10 and ISBN-13 pairs for the hardback and paperback?

Perhaps that is not permitted in OCLC - I don't know if paperback/hardback distinction merits a new record in OCLC.

If the high number of 2 ISBNs does not reflect the coupling of ISBN-10 and -13 pairs, might those records with 2 ISBNs represent simple hardback/paperback distinction?

Yours,
Kevin


> -----Original Message-----
> From: Bibliographic Framework Transition Initiative Forum
> [mailto:[log in to unmask]] On Behalf Of Myers, John F.
> Sent: Monday, May 20, 2013 1:26 PM
> To: [log in to unmask]
> Subject: Re: [BIBFRAME] Instance of ISBNs in MARC records
>
> Hmm, 2 ISBNs in 2nd place -- how many are situations of coupled ISBN-10
> and ISBN-13 pairs and how many are "distinct"? The "instance" plot
> thickens. :-)
>
> John F. Myers, Catalog Librarian
> Schaffer Library, Union College
> Schenectady NY 12308
>
> [log in to unmask]
> 518-388-6623
>
> -----Original Message-----
> Roy Tennant wrote:
>
> As requested, numbers from WorldCat, the 1 May 2013 Research snapshot,
> with 296,589,450 records:
>
> NO. of Recs ISBNs Percent
>
> 230402772 0 77.68%
> 58861390 2 19.85%
> 4269211 4 1.44%
> 1659221 1 0.56%
> 515674 6 0.17%
> 466645 3 0.16%
> 151133 8 0.05%
> 84572 5 0.03%
> 51967 10 0.02%
> 33372 12 0.01%
>
> Keep in mind that WorldCat, being the largest library union database in
> the world, includes a great deal of material that pre-dates the
> establishment of the ISBN.