Citation delay in interdisciplinary knowledge exchange

As part of a larger project to investigate knowledge flows between fields o f science, we studied the differences in speed of knowledge transfer within and across disciplines. The age distribution of references in three select ions of articles was analysed, including almost 800,000 references in journ al publications of the United Kingdom in 1992, 700,000 references in public ations of Germany in 1992, and more than 11 million references in the world total of publications in 1998. The rate of citing documented knowledge from other disciplines appears to d iffer sharply among disciplines. For most of the disciplines the same ratio 's are found in the three data sets. Exceptions show interesting difference s in the interdisciplinary nature of a field in a country. We find a genera l tendency of a citation delay in case of knowledge transfer between differ ent fields of science: citations to work of the own discipline show less of a time lag than citations to work in a foreign discipline. Between discipl ines typical differences in the speed of incorporating knowledge from other disciplines are observed, which appear to be relatively independent of tim e and place: for each discipline the same pattern is found in the three dat a sets. The discipline specific characteristics found in the speed of inter disciplinary knowledge transfer may be point of departure for further inves tigations. Results may contribute to explanations of differences in citatio n rates of interdisciplinary research.