I'll explain in a practical example: "War and Peace" is 1 book, but because it is such a large one, most publishers divide it into multiple volumes. I have the book in 4 volumes, and once read, my stats will say that I've read 4 books by Leo Tolstoy. It's not accurate, I've only read 1 book, it just so happens that it is divided in 4 physical volumes. I think we should be able to divide them in different volumes in storygraph (different ISBN, covers, page numbers, etc), but make them part of one single book, so the author stats (and other stats like moods/genres etc) are also correct.