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Scientists are increasingly overwhelmed by the volume of articles being published

A rapid rise in the number of academic articles being published could undermine public trust in science, researchers have warned.

The number of articles published worldwide rose from about 1.9 million per year in 2016 to a stunning 2.8 million in 2022 – an increase of 47% – despite little change in the number of scientists.

This surge has attracted widespread comment, but the new study provides detailed analysis of the situation.

It uses data on publisher growth, processing times of articles and “citation behaviours” (articles referencing each other).

It finds certain publishers, such as MDPI and Elsevier, have “disproportionately hosted” the growth – and sets out ways to address the issue.

“Public trust in science depends on science being done properly,” Dr Mark Hanson, from Centre for Ecology and Conservation at the University of Exeter.

“That means articles should be properly peer-reviewed, which takes time. It means some articles will be rejected, then either revised and improved or sent back to the drawing board.

“Our findings suggest that for some publishers that’s not happening.

“That’s bad for public trust in science because those articles clearly aren’t all being treated with normal standards of rigour.”

We’ve got issues

One publishing house featured prominently in the work: Multidisciplinary Publishing Institute (MDPI). MDPI has been behind about 27% of the growth added to the system since 2016, though it’s not alone.

Publishers like MDPI and Frontiers have enabled this growth by creating numerous “special issues” which publish articles with reduced turnaround times.

Special issues – also called “topics” or “collections” – focus on a particular topic, and traditionally arise from a conference or a pressing scientific subject.

However, the spike in special issues has been accompanied by changes in the definition of the term.

“Certain publishers took that label and removed the meaning of the word ‘special’,” said Dr Hanson.

Special issues work differently from normal research. Instead of authors submitting their work for peer review, guest editors are chosen to produce a special issue, and they can invite whoever they choose to write an article.

That is similar to the way things have traditionally worked, but in the new model very few articles are rejected, and peer review happens very rapidly.

The study found that MDPI had an average turnaround time of about 37 days, a fraction of other publishing groups. This low turnaround time was highly consistent across its journals.

“From submission to acceptance, you can’t properly peer-review most complex scientific papers in 37 days,” Dr Hanson said.

Impact inflation

The sudden rise in the number of articles published has created what the authors call “impact inflation”.

The “impact” of a journal is based on measures including citations: if a journal’s articles are commonly cited by others, the journal is seen to have a high impact.

That’s important for authors because journal impact is used to determine who gets grants and funding.

The new study also reveals high rates of “self-citation” (papers referencing other papers from the same publisher) in MDPI journals, which has drastically raised those journals’ profiles.

Commenting on how the situation might be addressed, Dr Hanson said: “Researchers face pressure to ‘publish or perish’ to be competitive for funding applications.

“While we highlight some groups, it’s really sector-wide. The funding bodies and regulatory groups will need to step in and define the line, then say who’s gone past it.”

The study’s authors received no funding for this work, and their data and the paper (entitled: “The strain on scientific publishing”) are published as a freely available preprint on arXiv.org at https://arxiv.org/abs/2309.15884.