Saturday, August 31, 2019
Science Alert, Some of The World's Most-Cited Scientists Have a Secret That's Just Been Exposed:
A new study has revealed an unsettling truth about the citation metrics that are commonly used to gauge scientists' level of impact and influence in their respective fields of research.
Citation metrics indicate how often a scientist's research output is formally referenced by colleagues in the footnotes of their own papers – but a comprehensive analysis of this web of linkage shows the system is compromised by a hidden pattern of behaviour that often goes unnoticed.
Specifically, among the 100,000 most cited scientists between 1996 to 2017, there's a stealthy pocket of researchers who represent "extreme self-citations and 'citation farms' (relatively small clusters of authors massively citing each other's papers)," explain the authors of the new study, led by physician turned meta-researcher John Ioannidis from Stanford University [A Standardized Citation Metrics Author Database Annotated For Scientific Field]. ...
One of those problems, Ioannidis says, is how self-citations compromise the reliability of citation metrics as a whole, especially at the hands of extreme self-citers and their associated clusters. "I think that self-citation farms are far more common than we believe," Ioannidis told Nature [Hundreds of Extreme Self-Citing Scientists Revealed in New Database]. "Those with greater than 25 percent self-citation are not necessarily engaging in unethical behaviour, but closer scrutiny may be needed." ...
Among the 100,000 most highly cited scientists for the period of 1996 to 2017, over 1,000 researchers self-cited more than 40 percent of their total citations – and over 8,500 researchers had greater than 25 percent self-citations.