Scientific citation
Scientific citation is providing detailed reference in a scientific publication, typically a paper or book, to previous published (or occasionally private) communications which have a bearing on the subject of the new publication. The purpose of citations in original work is to allow readers of the paper to refer to cited work to assist them in judging the new work, source background information vital for future development, and acknowledge the contributions of earlier workers. Citations in, say, a review paper bring together many sources, often recent, in one place. To a considerable extent the quality of work, in  the absence of other criteria, is judged on the number of citations received, adjusting for the volume of work in the relevant topic. While this is not necessarily a reliable measure, counting citations is trivially easy; judging the merit of complex work can be very difficult. Previous work may be cited regarding experimental procedures, apparatus, goals, previous theoretical results upon which the new work builds, theses, and so on. Typically such citations establish the general framework of influences and the mindset of research, and especially as "part of what science" it is, and to help determine who conducts the  peer review. Patent references. In patent law the citation of previous works, or prior art, helps establish the uniqueness of the invention being described. The focus in this practice is to claim originality for commercial purposes, and so the author is motivated to avoid citing works that cast doubt on its originality. Thus this does not appear to be "scientific" citation. Inventors and lawyers have a legal obligation to cite all relevant art; not to do so risks invalidating the patent. The patent examiner is obliged to list all further prior art found in searches. Citation frequency. Modern scientists are  sometimes judged by the number of times their work is cited by others—this is actually a key indicator of the relative importance of a work in science. Accordingly, individual scientists are motivated to have their own work cited early and often and as widely as possible, but all other scientists are motivated to eliminate unnecessary citations so as not to devalue this means of judgment. A formal citation index tracks which referred and reviewed papers have referred which other such papers. Baruch Lev and other advocates of accounting reform consider the number of times a patent is cited to  be a significant metric of its quality, and thus of innovation. Citation-frequency is one indicator used in scientometrics. Research. Some studies explore citations and citation-frequencies. Researchers found that papers in leading journals with findings that can't be replicated tend to be cited more than reproducible science. Results that are published unreproducibly – or not in a replicable sufficiently transparent way – are more likely to be wrong, may slow progress and, according to an author, "a simple way to check how often studies have been repeated, and whether or not the original findings are confirmed" is needed. The authors  also put forward possible explanations for this state of affairs.