Referees are given guidelines specific to each article type. They are generally asked to assess whether the research is scientifically sound, that is:
- whether the work has been appropriately put into the context of the current literature
- whether suitable methods have been used
- whether sufficient information and source data have been provided to allow others to repeat every step of the work
- whether the conclusions are supported by the findings.
For some article types, such as Case Reports or Opinion articles, referees are asked to comment on the facts and approaches used, not necessarily whether they agree with the author’s opinion.
In addition to their written report, referees also select one of three statuses:
- Approved: No or only minor changes are required. For original research, this means that the experimental design, including controls and methods, is adequate; results are presented accurately and the conclusions are justified and supported by the data.
- Approved with Reservations: The article is not fully technically sound in its current version, but the reviewer’s criticisms could be addressed with specific, sometimes major, revisions.
- Not Approved: The article is of very poor quality and there are fundamental flaws in the article that seriously undermine the findings and conclusions.
The approval status is shown on the article, together with the referee’s name and affiliation, and the detailed report supporting the status they selected.
If an author decides to revise the article to address the reviewers’ comments, all referees are invited to provide additional reports on the new version; in particular if they had originally given an ‘Approved with Reservations’ or ‘Not Approved’ status, we ask them to assess whether the work has been sufficiently improved to achieve a better approval status.