What it is, and what it is not
Developmental editors deal with content, organization, and genre considerations.1 An assessment reads at that level and stops there. It says what the manuscript is currently doing and where the problems are, and it leaves the solving to the author.
Editors Canada's structural editing standards describe the same territory from the other end. They ask an editor to assess and shape material to achieve a coherent structure and sequence, with a logical progression of ideas and a narrative or expository flow. They separately ask the editor to revise, cut, or expand text to meet length requirements, and to identify and either recommend or make deletions and additions.2
The word doing the work in that last standard is either. An assessment recommends. A structural edit may also make the change.
When the report is worth more than the edit
Three situations make the report the better purchase, and each of them is common.
The first is a manuscript whose direction is undecided. Where an author is choosing between two books, a structural edit implements one of them, and half the money goes into work the other version would not have kept.
The second is a first book by an author who wants to learn the craft rather than buy a result. A report names the patterns. An edited file supplies fixes, and a writer can read fifty fixes without seeing the pattern behind them.
The third is a budget that will not stretch to a full structural edit. A report on the whole manuscript is a real piece of work at a fraction of the cost, and an author can act on it over months.
Why a sample cannot substitute for it
The Editorial Freelancers Association is explicit about the limit. A brief sample edit or editing test can help in evaluating a service such as copyediting or line editing. Developmental editing is too large in scope to be captured by a short sample edit.3
The reason is structural rather than commercial. Organization is a property of the whole, and no reading of five pages can report on it. An assessment is expensive precisely because it requires the reading a sample avoids.
That is also why an assessment is priced closer to developmental work than to copy editing. The EFA's 2026 rate chart puts developmental editing at 3.0 to 3.5 cents a word for fiction and 4.0 to 5.0 cents for nonfiction, and the reading behind an assessment is the same reading.4
What a useful report contains
Four things belong in it, and an author is entitled to ask for all four before commissioning one.
The first is findings of fact about the manuscript. Those are chapter lengths, places where material repeats, sections announced and not delivered, and stated counts that do not match what is present.
The second is diagnoses, supplied with the evidence that produced them. A judgment that the middle third loses momentum is worth having when it names the chapters and the pages that prompted it.
The third is priorities. A report listing thirty findings without saying which three matter most has transferred the hardest decision back to the author.
The fourth is an explicit statement of what was not assessed. A structural report that says nothing about sentences is not incomplete, and saying so prevents an author from assuming the prose was approved.
Where the author's authority begins, which is immediately
An assessment does not decide what the book is for, which of two possible books to write, or whether a scholarly or factual claim holds. Editors Canada's fundamentals ask that editorial communications be clear, tactful, succinct, and actionable, and that significant changes be proposed or negotiated rather than imposed.5 A report is that standard applied to a whole manuscript at once.
Everything a client sends is treated in confidence, including unpublished manuscripts, outlines, and correspondence with an agent or a press. Our book editing is quoted on the whole manuscript, and what each level covers is published.
An author unsure which to buy can settle it with one question. Do you know what you want the book to be? If yes, an edit implements it. If no, an edit will implement whatever the manuscript currently is, which is the expensive way to find out.