Patent Overlay Mapping: Visualizing Technological Distance by Luciano Kay, Nils Newman, Jan Youtie, Alan L. Porter, Ismael Rafols.
Abstract:
This paper presents a new global patent map that represents all technological categories, and a method to locate patent data of individual organizations and technological fields on the global map. This overlay map technique may support competitive intelligence and policy decision-making. The global patent map is based on similarities in citing-to-cited relationships between categories of theInternational Patent Classification (IPC) of European Patent Office (EPO) patents from 2000 to 2006. This patent dataset, extracted from the PATSTAT database, includes 760,000 patent records in 466 IPC-based categories. We compare the global patent maps derived from this categorization to related efforts of other global patent maps. The paper overlays nanotechnology-related patenting activities of two companies and two different nanotechnology subfields on the global patent map. The exercise shows the potential of patent overlay maps to visualize technological areas and potentially support decision-making. Furthermore, this study shows that IPC categories that are similar to one another based on citing-to-cited patterns (and thus are close in the global patent map) are not necessarily in the same hierarchical IPC branch, thus revealing new relationships between technologies that are classified as pertaining to different (and sometimes distant) subject areas in the IPC scheme.
The most interesting discovery in the paper was summarized as follows:
One of the most interesting findings is that IPC categories that are close to one another in the patent map are not necessarily in the same hierarchical IPC branch. This finding reveals new patterns of relationships among technologies that pertain to different (and sometimes distant) subject areas in the IPC classification. The finding suggests that technological distance is not always well proxied by relying on the IPC administrative structure, for example, by assuming that a set of patents represents substantial technological distance because the set references different IPC sections. This paper shows that patents in certain technology areas tend to cite multiple and diverse IPC sections.
That being the case, what is being hidden in other classification systems?
For example, how does the ACM Computing Classification System compare when the citations used by authors are taken into account?
Perhaps this is a method to compare classifications as seen by experts versus a community of users.
BTW, the authors have posted supplemental materials online:
Supplementary File 1 is an MS Excel file containing the labels of IPC categories, citation and similarity matrices, factor analysis of IPC categories. It can be found at: http://www.sussex.ac.uk/Users/ir28/patmap/KaySupplementary1.xls
Supplementary File 2 is an MS PowerPoint file with examples of overlay maps of firms and research topics. It can be found at: http://www.sussex.ac.uk/Users/ir28/patmap/KaySupplementary2.ppt
Supplementary File 3 is an interactive version of map in Figure 1visualized with the freeware VOSviewer. It can be found at: http://www.vosviewer.com/vosviewer.php?map=http://www.sussex.ac.uk/Users/ir28/patmap/KaySupplementary3.txt