First time reviewer here. My purpose as a reviewer is to make recommendations on how the manuscript can be improved, right? In this effort, should I distinguish my solid expert opinion from mere suggestions?
For example, if I see an error, then I believe I should professionally but firmly point it out:
"X is not a valid conclusion because of y. It should be removed."
However, what if the issue is not a clear-cut error but rather a matter that, in my opinion, would strengthen the quality of the manuscript?
Should I use the same firmness? (Option A)
"X should be added because of y."
or distinguish this as an opinion (Option B):
"Perhaps it would be beneficial for X to be added. Consider including x due to y."
As an author on the other side of things, I would appreciate the distinction so that I understand what either needs to be changed in a revision (or needs to be strongly justified why the reviewer was wrong) versus what I can freely disagree with the reviewer about without having to make a strong justification about why I disagree.
This issue is giving me pause because I've rarely or never seen Option B in reviews of my own manuscripts. All comments by reviewers are similar to Option A.
My apologies if my examples are too vague. I tried to make the applicable to the whole community here which requires ambiguity unfortunately.