Goodreads Librarians Group discussion

You should combine, as for the guidelines in the combine editions page - different publications, different formats (hardcover, paperback, audio) and different translations of the same book.
Ebooks should be combined, then, with the "ink" versions.

Basically, unless the book has extremely different content, they need to be combined with the other editions of the same book. If you are unsure how different, ask here before combining.

To combine, click the "Other Editions" on the right side of the books page and then "Combine Editions" on the right side of the editions page. This will bring up ALL BOOKS by that author. You can then click the check boxes of each book that needs to be combined to each other and select COMBINE at the top or bottom of the page.

Just to clarify, Dutch: when editions are combined, they continue to have an entry for each edition. It's just that those entries appear as one book in lists of books, show all of their reviews together (unless specifically filtered), and list each other in the "other editions" box. You generally find books where their editions aren't combined -- so they look like more than one book -- by accident after a new edition is entered or imported without being combined with its other editions; that's where librarians come in! If editions aren't combined for a reason, there will usually be a librarian's note explaining that reason.

(We do occasionally merge editions, which actually deletes an entry. That's an entirely different operation and doesn't have anything to do with the format of the book editions. Don't delete any entries until you're more familiar with what that involves!)