I’ve likely said this before. Editing, proofreading and copyediting for science writers are all different tasks. All are vital steps along the road to writing a great manuscript, but they perform different (and sometimes overlapping) functions for you.
A proofreader will correct what you have written, in the way you have written it. If you write “Pandas is red and green”, a proofreader may simply change this to “Pandas are red and green”. A practiced proofreader will point out that pandas are black and white. But they will not be subject-matter experts, and although they are trained to look up statements of fact like that, they are more focussed on how things are said and may not be able to catch such errors. This is particularly true for science proofreading where the subject being proofread is very technical and the proofreader may not share your technical expertise.
An editor will judge and (hopefully) improve the presentation and meaning of what you have written. This is a much greater commitment than proofreading as it means potentially rearranging entire sections, some rewriting and either fact-checking or querying facts in addition to ensuring proper use of grammar. If a committed colleague or business is editing your document, you can expect some proofreading to be included. However, an academic committee member or journal editor will not be interested in proofreading and likely return your document to you unedited requesting that the grammar and usage be improved before submission. Hence, you may want to get a proofreader to read your work before sending it to an editor.
A copyeditor is focused on formatting but will also keep an eye out for grammar errors and errors of fact. By and large, the copyeditor will refer to the details of how a publisher wants the paper to appear in print and change the document to comply with those details. The instructions to authors is a copyeditor’s go-to document. While there is no need for you to have your document perfectly copyedited before submission, it certainly makes the editor happy if it is at least close. Certainly, a manuscript submitted that ignores these instructions will be rejected out of hand.
Before you seek help to proofread, edit or copyedit a document, it is good to know what you need. I hope this helps a bit.
John @ ProofreadCanada