I really didn't think of anyone changing anything in someone else's paper. I had in mind that if we were helping to check a paper, that we would point out spelling errors and grammatical errors that the person could check out themselves. If they decided that they agreed that each one was a mistake, they would check their dictionary or grammar book and correct it in their paper if necessary.
Also if something is unclear to me as a reader I would point that out as well but not tell a person how to fix it. Once again it would be up to the person to make any changes necessary to fix that problem.
I have read friends' papers for them and pointed out spelling and grammar errors and problems with comprehension, but I would never rewrite anything for them. I remember one time I asked someone to look at a letter I was writing for work and give me an idea of how it sounded. They sat down and began rewriting for me (which I had not asked them to do). It wasn't anything like the way I write so I couldn't even use their brand new sentences even if I had wanted to. I told them thank you very much and went into the office, threw their letter away, and started the letter over again in my way of writing. Looking at their way of writing only confused me because it was so different. That was the last time I ever gave someone a piece of writing and asked them for their ideas. LOL After that I only occasionally asked how to word a particular sentence but never a whole paragraph.
Anyway, that is why in my article about the completed essay I suggested that students might want to get someone to read their paper and point out spelling, grammar, and problems with comprehension, and suggested that they
not get feedback on the style or the arguments in the essay. I guess what we are referring to is more like proofreading than editing but that is a term used specifically in the book industry. There doesn't seem to be a general term for what we are really talking about.