ISBN's

[Krazykiwi]

I think it would be really useful to have something on the https://www.goodreads.com/help/show/2... page about how converting ISBN's between 10 and 13 works. Because while you'd have to do math to prove one is correct, it's really easy to see when one is wrong without a calculator if you know how (indeed, once you know how, they jump out at you when you run across one).

Additionally, I think that page is a good place to note the Kobo/B&N ID info (if it's included elsewhere, I didn't find it yet), because I know a few new librarians find the warning about nook id's a little intimidating.

Something like this is what I'm after:
ISBN's come in two formats: 10 digit and 13 digit. ISBN10's can begin with any number. Some older books leave the last digit off. ISBN 13's begin with 978 or (rarely) 979 and have 13 digits. The final digit of both is a checksum created by doing some maths on the rest of the numbers, so if it's missing, you can use an ISBN calculator to figure it out.

To be absolutely sure one is correct you'd have to use an ISBN calculator, but it's easy to see when the pair don't match just by comparing them:

ISBN13 -> ISBN10: Drop the 978, drop the last digit, what's left are the first 9 digits of the ISBN10
ISBN10 -> ISBN13: Add 978 to the start and drop the last digit, and you have the first 12 digits of the ISBN13

Example as they look on an edition page:
1476746583 (ISBN13: 9781476746586) (All the Light We Cannot See, Anthony Doerr)
0316055433 (ISBN13: 9780316055437) (The Goldfinch, Donna Tartt)

As you can see once you know how it's easy to see if the ISBN pair is probably right. If you instead saw this on the book page, you can be absolutely sure that it's not right:
031605543 (ISBN13: 978147674658)


and maybe something like this:

Non ISBN 13s that are allowed on GR in the ISBN13 field:
BN Id's (Nook) 13 digits, begin with 294. Set the format to "Nook".
Kobo Id's are 13 digits, begin with 123. Set the format to "ebook".

For both of these, the edit form will complain that it's invalid, but will save it anyway. This is probably the only time you should ignore that warning. Ebooks on both stores are only given a store ID if they don't already have an ISBN, so books not all books have them even if sold at those stores. Also remember librarians can't use B&N/Kobo pages to get info, only use store id's if they are posted by the author/publisher.

[Michael]

For conversions of ISBNs as well as checks for correctness use a tool like

http://www.hahnlibrary.net/libraries/...

Of course, GR could have provided automatic conversions (enter one, get the other for free) and checks, but that would make live for librarians way too easy...

[Krazykiwi]

There is a converter linked on that page already. I was hoping that if more librarians realised how easily you can spot which ISBN's go together without needing one (for instance, matching up when the isbn 10 and 13 are on different editions and can be merged) or conversely how easily you can spot when the 10 and 13 on an edition don't match, this is a useful skill to have.

You may still need to turn to a converter to confirm 100%, but for a whole lot of use cases, just eyeballing it is enough.