What is the arXiv?
The arXiv is a server that hosts ‘eprints’ or ‘preprints’ of research papers, and is a key publishing platform for many fields, particularly physics and mathematics. Founded back in 1991 by Paul Ginsparg, it currently hosts over 1 million research articles, with more than 8000 submissions per month!
Despite now being in the running for 25 years, the arXiv still represents one of the greatest technological innovations to utilise the Web for scholarly communication.
While the majority of the content submitted to the arXiv is subsequently also submitted to traditional journals for publication, there is still content which never goes beyond its confines. Irrespective of this, communities engaged with the arXiv still cite articles published there, whether or not they have been formally published in a journal elsewhere.
This is the whole purpose of the arXiv: to facilitate rapid peer-to-peer communication so that science accelerates faster. The fact that all articles are publicly available is incidental, and just happens to be a topic of major interest with the growing open access movement.
However, the arXiv is not peer reviewed in the formal sense. It is moderated, so that junk submissions can be removed, or manuscripts recategorised, but it lacks the additional layer of quality control of traditional peer review.
So while some might think this poses a risk, ask yourself this question: do you re-use articles critical to your research without making sure that you have checked and understand the research to a sufficient degree that you can appropriately cite it? Because that’s peer review, that is, and it applies irrespective of whether an article has already been peer reviewed or not.