Recent Advances


Multiple Databases

Greater coverage results in a more accurate map. The maps presented in this website includes data from Scopus and the USPTO. By including patent information, and tracking the science linkages within these patents, we can generate a much more accurate picture of how and where science contributes to innovative activity.

Multiple Theories

There are a variety of approaches that can be used to create maps of science and technology. These different methods are based in different theoretical perspectives of how science operates. We create maps using multiple theoretical perspectives to try to create the most accurate understanding of the structure and dynamics of science and technology.

The left-hand map below is based in a theoretical perspective that emphasizes “problem genealogies” – or how researchers cognitively frame the research problems on which they work, and how those frames change over time. This approach combines co-citation analysis, bibliographic coupling, and textual analysis. The map shown in the “Better Maps” section of this site was created using this methodology.

The right-hand map below is based in a theoretical framework that emphasizes “academic lineages”. This approach uses direct citation analysis, and thus relies on the direct linkages (lineages) between documents. Since direct citation includes self-citations, this framework tends to preserve the historical (rather than the cognitive) bases of the lines of research conducted by researchers and research groups.

The two maps are complementary. Although they are visually similar (indicating a robustness or consensus in science at high levels, they are different. When used together for analysis, they enable “Better Solutions”.

Problem Genealogies

Problem Genealogies map

Academic Lineage

Academic Lineage map