How different is different?

[John]

I was checking to see if my edition of Missing Susan by Sharyn McCrumb was already in the database. Checking by ISBN I found an edition there--same publisher, but with a two-month difference in publication date, an eight-page difference in page count, and a different cover. Obviously it would be silly to consider this a different edition; but how much of a difference makes it different? (And how do I know if the book on the screen is correct when it's not the same as the book in my hand?)

[rivka, Former Moderator]

Page count is often incorrect, so I would never go by that alone.

If it has a different cover, I'd go ahead and make an alternate-cover edition. Republishing a book with the same ISBN and a new cover is surprisingly common, particularly in certain genres.