I have a whole host of Christian nonfiction books that I have read, but cannot add them to my "Books I've Read" list.  I get this message, "I'm sorry, this book has a valid ISBN number but is not in our database".  My question is, if the ISBN number is valid, why isn't it in the database?

I also run into this problem when searching for certain Christian nonfiction books to order.  They're just not in the system. 

I know that I can add a book to the system, but this is a tedious process.  I'm just wondering why it isn't already there?

I found this in the help center:

Problem: You enter an ISBN on the Post Books page, and nothing happens.

Explanation:  First check that you are entering the ISBN correctly (see above).  If you are, then this means that the ISBN isn't recognized by the database.

The PBS database is compiled elswhere, and sometimes has missing items.  Many of these will be added in the future during routine database updates.  In the meantime, books with unrecognized ISBNs need to be Posted with customized listings, using the "Post a Book Without an ISBN" link on the Post Books page.

Solution:  You will need to post this book with a customized listing for the book, using the Post Books without an ISBN link on the Post Books page.

Pat, a long shot here, but have you checked the copyright page to see if there isnt a different ISBN there? Also check and see if they are listed by the ISBN on another site, like amazon.com? Or are they books that are only available new from the publisher, like the Baptist Sunday School Publishing Board? If that is the case, then the publisher may not be adding the information to be included in any data bases but their own. 

In answer to this question:

" My question is, if the ISBN number is valid, why isn't it in the database?"

The "ISBN number is valid" message just means that the number follows the rules for ISBN numbers.  One of the digits (the last one, I believe) of the ISBN number is a checksum digit.   A checksum digit is used in computer data to verify that a value hasn't been corrupted (a wrong digit entered).  A simple form of checksum digit is to add all the other individual digits together, divide by 10 and the remainder is the checksum.  If any of the other digits was entered incorrectly, then the checksum calculated on that wouldn't match the checksum in the value, indicating that the value is not a valid value.

[Note that it is possible for errors in more than one digit to result in a checksum digit that matches.  There are variations on checksum that use more digits to identify, and in some cases even correct invalid digits.  These are called "Hamming codes".  Although I've probably told you more than you want to know, for more information, see http://en.wikipedia.org/wiki/Checksum and http://en.wikipedia.org/wiki/Hamming_code

So to summarize - the digits in your ISBN value form a valid ISBN number.  However, not all ISBN numbers have been assigned (we were getting close, which is why ISBNs were recently enlarged to 13 digits from 10).  In your case, it sounds like the ISBN has been assigned, but the publisher may be somewhat obscure and so the title hasn't been entered yet in some databases.  There is no one single global database that maps all isbns to titles.  ISBNs are often issued in blocks to publishers who use them up over time.

Another possibility...not every book in the universe is in the PBS database right now.  They are working towards that, of course, but it's a slow process.  So, in  regards to the message that this is a valid ISBN but the book is not in the database...the books will likely get added now that you've searched for them.  When someone does a search for a book that PBS does not have in the database, that is recognized and usually gets added within a few days.  So, re-do your search on monday and see if they come up.

If the ISBN is valid you DO NOT have to enter it as if there is no ISBN number.  I learned this trick not to long ago.

Enter the ISBN as normal and when a description doesn't pop up to the right click on the Check box (or whatever that button is right below where you entered the ISBN)

Once you do that it will bring up a page where you enter all of the details.  This is much like the page that you use when the book doesn't have an ISBN but this allows you to set it up and include the ISBN.

so you'll still have to go a few extra steps but at least you will have set it up with the ISBN and not a fake number!

This was a very informative thread. Thanks for posting this, Pat. And thank you eveyone else for the good information.

I also learned some new information about ISBNs here.  A special thanks to Bret for his knowledge, and also to Leslie for re-posting information about adding a valid ISBN book to the system when ISBN isn't yet in PBS.  (Always good to see that information displayed, I think folks tend to forget about this and/or don't know this procedure.)

Wow, that was a lot of great info.  Thanks to all!  I think you all made valid points...but I'm still frustrated because I read a LOT of books from this particular publisher, but have to pay full price for them because they are NEVER on PBS:(

I realize that I can add the info myself, but then there's the issue of obtaining a photo of the book.  I rarely order books that have no photo available or limited information.

As for being an "obsure" publisher, I suppose that might be a correct description.  It's the Pentecostal Publishing House.  They have their own catalogue, website and such...

So, should I contact the publisher of all these wonderful books or R&R to request their inclusion in PBS?