Measuring science-based science linkage and non-science-based linkage of patents through non-patent references

This paper analysed the citations of patents to science- and non-science-based references as an agency of the linkage between technology and science. A review of the literature identified a variety of techniques of measuring science linkage (SL) with various results. Therefore, this study aimed to compare the differences between science-based SL and nonscience-based linkage (NSL). Patent data were collected from the United States Patent and Trademark Office database for the past two decades. Results showed a phenomenon of rapidly growing NSL of patents at different levels of technological fields and firms. In addition, field- and firm-specific differences in the linkages between science and technology were identified. This study analysed various types of SL performances of the top 20 firms in the Computers and Communications field and found that science-technology linkages were stronger in Lucent, Mitsubishi and Microsoft. It is worth noting that Texas Instruments (TI) was ranked thirteenth in science-based SL but third in Relative SL Ratio. Based on the Relative SL Ratio, TI's science-based SL was much higher than its NSL. (C) 2015 Elsevier Ltd. All rights reserved.