From the Impact Factor to DORA and the Scientific Content of Articles
Authors: Seppo Ylä-Herttuala
Journal: Molecular Therapy (2015)

The use of the impact factor (IF) to rank the importance of scientific journals has been controversial for well over a decade.1Vanclay JK Impact factor: outdated artefact or stepping-stone to journal certification?.Scientometric. 2012; 92: 211-238Crossref Scopus (251) Google Scholar,2The PLoS Medicine Editors. The impact factor game.PLoS Med. 2006; 3: e291Crossref PubMed Scopus (336) Google Scholar Funding institutions and various research evaluation bodies increasingly use the IFs of the journals in which an author has published as surrogates for assessing the quality of scientific work published by a scientist and his or her institution. Furthermore, the editorial policies of many journals can be manipulated so as to inflate the IF calculation. Regardless, it is clear to all that an IF applies solely to a journal and not to the individual papers it publishes. Notwithstanding the value of some sort of journal metric, we all know the limitations of the IF: citations to papers published in most journals typically follow a highly skewed distribution, with a handful of papers being highly cited but the majority attracting only modest numbers of citations. The IF also greatly varies between subject areas and over time, and can be influenced by factors such as the relative number of review articles vs. primary scientific reports. An IF based on the median number of citations would look quite different. Furthermore, the limits on word count and number of references imposed by many journals favor citations to review articles rather than primary articles, which further skews relative IF calculations. Thus, it is clear that the IF of a given journal does not necessarily reflect the quality of the research papers it publishes. In 2012, the San Francisco Declaration of Research Assessment (DORA; http://am.ascb.org/dora) was published to spark discussion of alternatives to the use of the IF in assessing contributions by individual scientists, as well as in hiring, promotion, and funding decisions. The basic message of DORA is that the scientific content of a research paper is much more important than the IF of the journal in which it appears. It further notes that research output encompasses many other factors, such as data sets, software, and impact on policy and practice. Following from this, a deeper view of scientific performance could be obtained by utilizing improved article-level metrics combined with other tools, such as the five-year IF, the eigenfactor, and the h-index. Among other points, DORA recommends that unnecessary constraints on number of references should be avoided and, when appropriate, editors should mandate citation of the primary literature rather than review articles in order to credit scientists who originally reported a given finding. However, the DORA proposal will not fully solve the problem of IF dominance because evaluation of the scientific merits of individual published articles for purposes of making promotion or funding decisions will be very laborious and subject to natural variation between evaluators’ opinions as well as the competence of the evaluators. Furthermore, top-tier research in a narrow niche area may not be recognized by evaluators working in more mainstream research areas. Hence, we may need a DORA 2.0 to provide further guidance. The editorial process at Molecular Therapy relies on quality expert reviewers with the requisite expertise to evaluate the various aspects of any work. In this way, we offer our readers the best reports of original scientific results and significant advancements in the field, thus endorsing the spirit of DORA. While the IF continues to be an important benchmark of the success of the journal, Molecular Therapy does not practice any inappropriate manipulation of metrics. We believe that publishing scientific findings in a journal that effectively reaches your peers and colleagues working in the same field is the best approach to ensuring visibility and recognition of the value of primary observations and contemporary advancements in science.