Research Evaluation March 2010 0958-2029/10/01019-09 US$12.00 © Beech Tree Publishing 2010 19 Research Evaluation, 19(1), March 2010, pages 19–27 DOI: 10.3152/095820210X492503; http://www.ingentaconnect.com/content/beech/rev Identification of converging research areas using publication and citation data Reindert K Buter, Ed C M Noyons and Anthony F J van Raan Converging research is the emergence of new interdisciplinary research from fields which showed limited mutual interdisciplinary connections before. We describe three search strategies to identify converging research using data extracted from the WoS, including the social sciences and humanities. The field-to-field references (FFR) strategy uses citations from one journal subject category (JSC), to another; the keyword sets (KWS) strategy tracks the co-occurrence of keywords from different JSCs; and the affiliation patterns (AFP) strategy traces the co-occurrence of fields of research in author affiliations of papers. Resulting publication sets were assessed using data such as journal names, titles of publications, and titles of cited publications. Experts validated nine converging research areas that were detected using the KWS and FFR strategies; none were found with AFP strategy. N FEBRUARY 2008, the Lancet published an article on the outcomes of a trial which studied the effects of a treatment with probiotics on patients suffering from severe acute pancreatitis (Besselink et al, 2008). The most significant out- come of this study was an increased risk for mortal- ity in the group that was supplied the probiotics, and the study was stopped prematurely. In the same issue, the Lancet published an editorial bearing the suggestive title ‘Probiotics or con’, which was de- voted to this grave outcome and its larger conse- quences. The editorial concluded that without further research, it was no longer tenable to regard the use of probiotics in consumer products as completely risk-free. This trial and its editorial response illustrate an in- teresting interdisciplinary phenomenon. First, probi- otics, which are well-known food additives, were included in the treatment of severely ill people. Next, following the suggestion of the Lancet edi- torial, probiotics as food additives should now be scrutinized due to the outcome of this application. In a sense, this would complete an interdisciplinary circle, where a result (probiotics) from one field (food sci- ence and technology) influences research (trial study) in another field (clinical medicine) and vice versa. Developments such as this, where distinct re- search areas start to apply problems and tools from one another, possibly leading to new research directions or even new research areas, are consid- ered examples of converging research in this article. More formally, we define converging re- search as the emergence of new interdisciplinary research from fields which showed limited mutual interdisciplinary connections before. In this defini- tion, emergence is understood as the appearance of thematically related research which shows a sig- nificant growth in the number of publications. Also, the converging research is the result of re- search in two areas which had limited interdiscipli- nary connections before, and is thus both new interdisciplinary research, and a novel combination of disciplines. Our definition explicitly excludes intra-disciplinary emergence (i.e. within fields), and emergence of this type was not considered in our research. The publication of the report on the NSF/DOC- sponsored workshop ‘Converging Technologies for Improving Human Performance’ (Roco and Bain- bridge, 2003), was important for the widespread in- troduction of the notion of converging research. I Reindert K Buter (corresponding author), Ed C M Noyons and Anthony F J van Raan are at the Centre for Science and Tech- nology Studies (CWTS), Leiden University, Wassenaarseweg 62a, P.O. Box 905, 2300 AX Leiden, The Netherlands; Email: buter@cwts.leidenuniv.nl; Tel: +31 (0)71 527 3904.