Q: What’s 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. The best explanation I know came from Rachel Starr Thomson, who taught a course called “Substantive Editing for Nonfiction and Memoir” through The Christian PEN: Proofreaders and Editors Network, one of the professional associations I belong to.
I’m paraphrasing here, but Rachel said developmental editing is bringing into existence a manuscript that does not already exist, or completing one that’s unfinished. Substantive editing is working on a manuscript that is finished but may be in very rough shape. Both involve creative work, because a substantive edit may involve rewriting large parts of the manuscript. But developmental editing involves writing parts of the manuscript that don’t exist. It borders on ghostwriting.
Some writers want guidance in the creation of their manuscript, but don’t want the writing done for them. That still falls under the developmental category, because the editor still provides guidance, but without doing the writing. It’s important when you’re choosing an editor to work with that you understand what kind of help you’re looking for and be clear about what sort of input you want from your editor or writing coach. It’s your book. A freelance editor’s goal is to help you realize your vision for it, in whatever way works best for you.