Traces of Prior Art : An Analysis of Non-Patent References Found in Patent Documents

Research in the area of innovation has pointed out the relevance of conceiving innovation as processes in which a multitude of actors and a variety of interactions play a role. Integrative notions like (national) innovations systems, (techno-scientific) networks, or the triple helix metaphor, have been widely accepted as relevant to grasp the complexities entailed. This development highlights the need for indicators that mirror the dynamics involved. This contribution presents an in-depth examination of the role of "Non-Patent references", found in patents. After examining the occurrence of these references in the USPTO and EPO patent systems, the precise nature of these references is delineated by means of a systematic content analysis of two samples of non-patent references (n=10.000). Our observations reveal the relevance of 'non-patent references' for developing indicators to depict the proximity of technological and scientific developments. Application areas, limitations and directions for future research are discussed