Should revised editions of books be combined?

[Dannii]

I'm seeing conflicting answers about whether revised editions of books should be combined together. I think the answer is probably yes based on what I've seen, but I'd appreciate if there are any guidelines for when this shouldn't happen - if the changes are too substantial for example?

I have in mind these books:
Editions 1-3: https://www.goodreads.com/book/show/4...
Edition 4: https://www.goodreads.com/book/show/1...

It's possible these ones have only not been combined because they changed the title.

[rivka, Former Moderator]

Yes, they should be combined. Might wish to indicate which are the 4th edition (using the edition fields) first though.