Q: What is the difference between developmental editing and substantive editing?
A: That depends on whom you ask. Seriously, even editors can’t agree amongst ourselves what’s what, which is why each of us has some kind of web page where we define different types of editing in our own terms.
Substantive is an especially squishy term—I’ve heard it applied to several different kinds of editing.
Developmental editing can describe the process whereby an editor helps a writer develop a book from a concept, but it may also apply to an editor working on a rough manuscript to address big-picture issues. In a novel this includes character and plot and how they combine to form the story. In nonfiction it encompasses things like what topics will be included and in what order. Developmental editing includes structural revisions like adding and deleting whole scenes and even chapters. The editor will give the writer guidance on which parts need to be deleted, added, or rewritten, usually in the form of an editorial letter or report. They don’t do the rewriting for them; that would be more like ghostwriting. When this kind of edit is performed on a complete but rough draft, some folks call it content editing.
A substantive edit can entail major rewrites to some segments, but usually not restructuring. The editor may rewrite some passages, but they won’t usually add whole scenes unless the writer has specifically asked them to. For example, I once had a client who got stuck writing the breakup scene in a novel and asked me to do it. The substantive editor might delete segments that are deemed extraneous, but usually they will just flag them with a comment and leave that up to the writer. Some folks also call this process content editing.
As the Editorial Freelancers Association notes on its definitions page, “…the terms ‘developmental editor,’ ‘substantive editor,’ ‘structural editor,’ and ‘content editor’ overlap and are sometimes used interchangeably….” Christian Editor Connection has some more detailed definitions, as does Reedsy. (Full disclosure: I belong to all three of these organizations.)
See, the tricky thing about editing terms is that there are no International Organization for Standardization rules for naming them. So it’s important when you’re working with an editor to understand what kind of help you’re looking for and be clear about what sort of input you want from them. It’s your book, and the editor’s goal is to help you realize your vision.