This particular audio book doesn't say if it's unabridged or abridged anywhere on the box or the CDs.  My go to source is www.worldcat.org, but this particular audio book even has worldcat stumped.  I know this isn't really a question about PBS, but I thought maybe you guys would have an answer for me anyway.  Where else do you go for details on books?

Amazon or Goodreads. Athough in the absence of info, I would guess unabridged.

try inputting the ISBN in Google. 
 

Amazon often has incorrect info, since info is sometimes input by members.  I'm not looking to just google, I'm looking for a reputable site to find correct info.  Something that librarians or people that need absolutely correct info would use.  On this particular book, www.worldcat.org lists it as both abridged and unabridged and also lists it with a question mark.  So anyone have any reliable sites to use?

What's the ISBN? I'll see what I can find.  You're right that Worldcat is a go-to resource for that sort of information.  It is possible they released 2 editions with the same ISBN, both abridged and unabridged.  You might want to use a Requestor Condition for that book, if a specific version is important to you.

You could try powells.com. I'm not sure if that would help.

i have looked on audible.com and they give the length of the book and I think all of thiers are marked abridged or unabridged.  if the hours match the unabridged I would say it is unabridged.

But I don't think the audiobooks require you to say if it is abridged or not.  So if the description on paperbackswap does not say one way or the other and you match the isbn and media type, I think that is all that is required.

I'm just looking for the info for me, for an audio book that I have, so that I know what it is.  Whenever I have a question, I look them up on worldcat and figure it out, but this one lists several editions on worldcat - all with the same number of CDs - at least one says abridged, at least one says unabridged, one has a question mark, and some don't say either way.  It's just odd.  I probably should've written which book it was when I posted this, because now I'm not sure.  lol.  I'll figure it out and check the sites you guys have listed.  If anyone else has any sites with good info, I'd love to hear about them.  Thanks!

I use a variety of sites when editing book data, though WorldCat is the one I trust most with regards to abridged/unabridged info.  If it isn't there, then there isn't any one site I use for backup (except perhaps the publisher's own site, if it is listed there and still in print).  I have to dig around, see what several other sites have to say, and then consider whatever info I find -- is there a consensus? what info seems most reliable? etc.  I know that sounds a bit haphazard, but sometimes there isn't a good or easy option.

To echo what Melanie said:

It is possible they released 2 editions with the same ISBN, both abridged and unabridged.

That is something to look for when you find the info is contradictory on different sites.

You can check out the number of pages in the unabridged book.  An audiobook may be able to fit, say 25 to 35 pages per hour.  (That's my own estimate from comparing print books to audio books, nothing official.) So take the number of pages in the non-large print book, and divide by the number of hours in the audio book.  Then adjust for a slow or fast reader and, if you have that info, whether the font and page size of the book is particularly large or small.  If you end up with, say 50-80 pages per hour, it's likely abridged -- or being read by Alvin and the Chipmunks.

Even better: find an unabridged print copy of the book (or, if it's an older book, find the text of the book online.)  Pick a part of the print book that is description rather than action.  Then listen to that same passage in the audio book while following along in the print book.  An abridged audio book will generally cut or shorten descriptive passages.

How many discs is it?  The books I listen to generally have around 5 discs for abridged, and 10+ for unabridged - depending on the original length of the book.  A little more than an hour per disc.

Often if its read by a known actor, it's likely abridged. But number of discs are a good check too. 3 or 4? I'd say abridged.