Traditional models of peer review occur pre-publication by selected referees and are mediated by an Editor or Editorial Board. This model has been adopted by the vast majority of journals, and acts as the filter system to decide what is considered to be worthy of publication. In this traditional pre-publication model, the majority of reviews are discarded as soon as research articles become published, and all of the insight, context, and evaluation they contain are lost from the scientific record.
Several publishers and journals are now taking a more adventurous exploration of peer review that occurs subsequent to publication. The principle here is that all research deserves the opportunity to be published, and the filtering through peer review occurs subsequent to the actual communication of research articles. Numerous venues now provide inbuilt systems for post-publication peer review, including ScienceOpen, RIO, The Winnower, and F1000 Research. In addition to those adopted by journals, there are other post-publication annotation and commenting services such as hypothes.is and PubPeer that are independent of any specific journal or publisher and operate across platforms.