Peer review is the evaluation of work by one or more people of similar competence to the producers of the work (peers). It constitutes a form of self-regulation by qualified members of a profession within the relevant field. Peer review methods are employed to maintain standards of quality, improve performance, and provide credibility. In academia peer review is often used to determine an academic paper’s suitability for publication. In parallel with these ‘common experience’ definitions based on the study of peer review as a pre-constructed process, there are a few scientific understandings of peer review that do not look at peer review as pre-constructed. Hirschauer proposed that journal peer review can be understood as reciprocal accountability of judgements among peers. Gaudet proposed that journal peer review could be understood as a social form of boundary judgement – determining what can be considered as scientific (or not) set against an overarching knowledge system, and following predecessor forms of inquisition and censorship. Peer review can be categorized by the type of activity and by the field or profession in which the activity occurs, e.g., medical peer review.