We ask referees to return evaluations in six weeks. After about a month, we politely remind holdouts by E-mail, and we have been gratified by how effective such reminders are. Reviewers may recommend that manuscripts be accepted, accepted with revisions, or rejected. Very few reviewers recommend acceptance without revision, and we have yet to publish such an article. We expect referees to include substantive comments on content and how the paper should be revised for publication.
Most reviews are thorough and intended to help the author improve the work.
Every now and then, we receive an evaluation form without accompanying explanation - such reviews may salve the reviewer's conscience, but they do neither us nor the authors any good. We prefer four reviews before we make a final decision on a manuscript, but we will act on three. Sometimes the best we can do is two reviews, and in those cases, I act as a third reviewer. Deciding the fate of many manuscripts is relatively easy - the reviewers pretty much agree one way or the other. On those MSS with mixed evaluations, not only do I read the reviewers' comments carefully, but I also read the complete manuscript before making the final decision.