Abstract
Peer review in science was established in the 17th Century and while not without detractors and some controversy, has been a mainstay of high-quality scientific publications ever since. Most believe peer review adds substantially to the value of papers that achieve publication. However, in practice, peer review can be practiced with varying degrees of rigor and the value of the review depends on rigor. The two primary tasks of a reviewer are to determine whether the manuscript makes a substantial contribution (in an age of information overload) and to determine whether there are any "fatal" flaws. If the reviewer recommends rejection, then he or she need only note the major flaws. If, however, the material is sufficiently novel and would substantially add to the literature, the reviewer's secondary task is to ensure completeness and clarity by noting information that should be added and identifying unclear points; in these cases more detailed reviews are merited. To achieve this task, the reviewer must ask numerous questions related to the background and rationale, questions or purposes, study design and methods, findings, and synthesis with the literature. In this brief review I outline such key questions. An invitation to review is an honor and reflects the confidence of the editor in the reviewer's expertise and accomplishments. Given proper reviews and recommendations, the majority of authors believe peer review adds great value to their papers and the reviewer makes contributions to the community and their own knowledge.