Interactive overlays of journals and the measurement of interdisciplinarity on the basis of aggregated journal–journal citations

Using the option Analyze Results with the Web of Science, one can directly generate overlays onto global journal maps of science. The maps are based on the 10,000+ journals contained in the Journal Citation Reports ( JCR ) of the Science and Social Sciences Citation Indices (2011). The disciplinary diversity of the retrieval is measured in terms of Rao‐Stirling's “quadratic entropy” (Izsák & Papp, 1995). Since this indicator of...