Interactive overlays: A new method for generating global journal maps from Web-of-Science data

Recent advances in methods and techniques enable us to develop interactive overlays to a global map of science based on aggregated citation relations among the 9162 journals contained in the Science Citation Index and Social Science Citation Index 2009. We first discuss the pros and cons of the various options: cited versus citing, multidimensional scaling versus spring-embedded algorithms, VOSViewer versus Gephi, and the various clustering algorithms and similarity criteria. Our approach focuses on the positions of journals in the multidimensional space spanned by the aggregated journal–journal citations. Using VOSViewer for the resulting mapping, a number of choices can be left to the user; we provide default options reflecting our preferences. Some examples are also provided; for example, the potential of using this technique to assess the interdisciplinarity of organizations and/or document sets.

► Using VOSViewer, we provide an interactive overlay technique based on the full journal set of the Science Citation Index and the Social Science Citation Index 2009 combined. ► The differences between MDS and spring-embedding algorithms such as Kamada and Kawai (1989) are discussed in terms of the different topologies involved. ► Examples of (and instructions for) interdisciplinary journal mapping are provided.