A PATENT-BASED CARTOGRAPHY OF TECHNOLOGY

We use bibliometric (in particular patent-based) methods and techniques to develop a cartography of technology. Two types of maps are presented: co-word maps and co-classification maps. Both types of maps have been constructed for the entire domain of technology (the macro-level), i.e. the ensemble of all fields of technology in their mutual relations. Time series clearly illustrates the changing relations between the major clusters of technology, and in particular the changing role of fields which act as a ''bridge'' between clusters, or as a (declining or emerging) centre of technological activities within a specific cluster. Maps visualize relations between fields of technology. In order to have measures of the relative strength of these relations, we develop the concept of affinity between fields. A special feature of our macro-maps concerns the role of Japan in technology. A second hierarchical level is the combination of several fields of technology (meso-level). As an example we constructed a co-word map for the emerging ''crossroad'' technology optomechatronics based on patents as well as on scientific publications. In this way, optomechatronics is mapped from a technological point of view, and from a research point of view. The third hierarchical level concerns one specific field of technology (micro-level). Co-word maps have been constructed for the technology fields coating and crystal growing, optical equipment, and building materials. An important aspect of the map is the possibility to identify centers of activity within a specifically defined field of technology. These centers of activity may indicate important innovative developments, or they may reflect important markets. Furthermore, we introduce the concept of ''technological peripheries'': for a specific technology field one may identify the direct ''surroundings''; i.e. the most strongly linked fields. Also, first attempts are made to map the ''science and technology interface'' by a specific combination of publication and patent data. Our general conclusion is that the mapping methods and techniques presented in this publication already offer a unique way to visualize developments in fields of technology, and within technology as a whole. We emphasize that our technology maps are intended as a support tool, and never as a replacement of experts.