We like to believe that science is self-correcting, that scientific error — the result of sloppy methodology, miscalculation, or worse, intentional fraud — is eventually detected and expunged from the scientific record. We like to believe that retraction notices reach their intended audience, yet we know that retracted articles are often cited as if they were valid studies for years after retraction.
Why do retraction notices fail to reach readers? What is it about the scientific communication process that allows retracted articles to live a secret life, promulgating inaccurate — and sometimes harmful — information to scientists and the general public? And what, if anything, can be done about it?
Last year, with a grant from CrossRef, I investigated some of these questions in a paper published in the July 2012 issue of the Journal of the Medical Library Association, entitled “The Persistence of Error: A Study of Retracted Articles on the Internet and in Personal Libraries.”
In this study, we documented the location of retracted articles on public websites, outside the control of journal publishers. We also peered into the secret life of retracted articles living in personal libraries by studying records in Mendeley, a popular tool for managing references and sharing papers.
Of the 1,779 retracted articles identified in MEDLINE, published between 1973 and 2010, we were able to locate 321 publicly accessible copies, 95% of which were the publishers’ version and just 4% were final manuscripts. The most frequent site for access to retracted articles was PubMed Central, which provided public access to 138 (or 43%) of them. 94 (or 29%) of retracted papers were found in educational domains (on personal, lab and departmental websites), and just 10 (3%) were located in institutional repositories. Commercial websites hosted 24 (7%) of these retracted papers, which were used to promote a particular health product (e.g. dietary supplement) or medical intervention (e.g. surgery). Just 15 (5%) of these publicly accessible retracted papers included a retraction statement. 1,340 (75%) of these papers were found as records in personal Mendeley libraries, shared by 3.4 users, on average.
While readers often benefit from the many informal channels of access to the scientific literature, these newfound sources may come with the cost of promulgating erroneous and sometimes fraudulent information.
Authors who upload copies of their papers to a public website have little incentive to replace them–sometimes years later — with a watermarked “RETRACTED” version. Ditto for articles downloaded and saved in a personal library. And while PubMed will display a retraction notice in article record (example), a simple Google search will bypass these notices and take the reader directly to the fulltext and PDF version of the article on PubMed Central, both of which lack the retraction notice.
Earlier versions of retracted papers–living their secret lives as final author manuscripts–persist in institutional repositories years after they were retracted from the journal literature. This takes place, in part, because most institutional repositories are not designed to remove, update or append what is deposited in them. They are also run by individuals who lack the oversight that would allow such changes to take place. Repositories are run by librarians, not editors.
Stemming the propagation of bad science in a decentralized, multi-version document environment is not easy and it will likely require a number of different solutions targeted at different stages:
- Discovery--Alerting readers that an article has been retracted at the search and retrieval stage through bibliographic and citation coupling of the article with the retraction notice.
- Reading–Providing status updates for articles with services such as CrossMark.
- Writing–integrating status lookup functions into reference managers like Mendeley and EndNote.
- Publishing–detecting retracted references in bibliographies during the manuscript review process.
While none of the proposed solutions can independently halt the persistence of error in the literature, taken together, they may help to greatly minimize its effects.