More papers, less progress?

Slowed canonical progress in large fields of science

This thought-provoking article was published in PNAS a few months ago. The authors analyze the Web of Science dataset containing ~ 90 million papers and ~1.8 billion citations to quantify how the size of a discipline correlates with its rate of innovation and disruptive advances.

One measure of innovation is the rate at which new papers accumulate citations. Larger fields exhibit a rich get richer effect, with highly-cited papers disproportionally accumulating new citations. Thus, established ideas become entrenched, while potentially disruptive new ideas may get lost in the crowd of less-read and less-cited papers and forgotten.

The growth of physics has been easy to see even during my short career. The size of the daily arXiv postings has doubled since the time I was a PhD student. It is impossible to carefully read all of the new papers relevant to one's field - there is not enough time! We need to work together to not just promote our own work, but also spread the word to colleagues and collaborators whenever some exciting new idea appears in the daily posting.

The authors list some potential remedies to reduce the quantity of publications, but admit there is no perfect solution. For example, proscribing a limit to the number of annual publications incentives safer, follow the leader-type research that is more likely to attract a healthy number of citations. 

Senior researchers are not publishing more frequently to advance their own careers, but to ensure their students and postdocs have a chance on the hyper-competitive academic job market. This will continue as long as hiring committees and funding agencies base decisions off simple metrics such as citation counts.

More sophisticated metrics such as the "disruption measure" mentioned in the paper may be a better way to quantify the impact of publications. Unfortunately truly disruptive ideas may not be recognised quickly enough; fixed-term academic contracts rarely last more than a few years.

On the other hand, perhaps the use of bibliometrics is too narrow a way of quantifying scientific progress. Growing publication rates is also indicative of a growing, highly-skilled workforce capable of innovation in other areas.  A PhD does not lock you into an academic career forever.

What do you think?