What are preprints? Premium

Preprint papers are publicly available scientific papers before peer review, popular among open-access advocates and scrutinizing peer review practices.

A preprint paper is a scientific paper that is made available for reading to the public at large before it has been sent for consideration by a peer-reviewed scientific journal.

Once a group of scientists finishes conducting a study and has made specific conclusions with the data, the next step is to publicise their findings. The main way to do this today is by writing up their efforts and findings in a paper, then publishing it in a journal — preferably a journal published by one of the few reputed publishers or indexed in a database of such publishers. If the journal is peer-reviewed, the journal’s editor would share a paper they have received for consideration from scientists to three to five independent scientists working in the same field for their comments. If their comments are positive, the journal accepts the paper for publishing.

A preprint is a paper that scientists have written up and uploaded to a preprint repository, where it can be read by anyone who can access it. If the repository is on the internet, then anyone with an internet connection can read it. After uploading their paper as a preprint, the authors may or may not send it to a journal for peer-review and publishing.

During the COVID-19 pandemic, a record number of preprints were published around the world, as scientists wanted to publicise their research about the disease and potential cures without waiting for a journal to peer-review and publish them, which often takes many months. Post-pandemic reviews have however found a lot of this research to have been of low quality — a criticism many scientists have levelled against all preprints in general.

The quality of science in preprints varies depending on the field as well as the preprint repository. arXiv (pronounced ‘archive’) is the world’s largest and oldest repository, hosting preprints on mathematics, physics, astronomy, engineering, and quantitative biology, and some other similar topics. It has its own moderation system that keeps out papers with questionable or bad science. Since it was launched in 1991, other repositories like bioRxiv (biology), chemRxiv (chemistry), medRxiv (medicine), PsyArXiv (psychology), and SSRN Electronic Journal have also come up.

Today, preprints are popular among open-access advocates, who celebrate the fact that they are available for free to read whereas scientific journals often charge readers a hefty fee to read individual papers.

The popularity of preprints has also turned an interrogative spotlight on peer review, since that is the main difference between a preprint and published paper. Journals have historically used peer review to judge whether a paper is of good quality, and journals have also become notorious for their substantial profit margins. An increasing number of critics have pointed out that peer review fails to catch research that has been deliberately faked.