at Leiden is very active in this area, as is the Science Policy Research Unit at Sussex University in the United Kingdom. Similar work is done in Manchester, England. A number of other groups in Europe also carry out large scale bibliometrics research. In part this is because many European countries have a centralized responsibility for science (centralized in one agency or group) and within the European Economic Community there are central groups responsible for the function of the scientific establishment. Europeans thus have an administrative motivation to look at science as a whole and to try to develop tools for measuring performance.

We also do a lot of work in technology-oriented areas and in "patents citing patents." Most of this work is done for private clients and is not publicly available. We do a lot of competitive intelligence work and cross-licensing work as well as technology tracing. We have written papers about this work, but generally we do not say much about it.

In this article I discuss the third type of bibliometrics(the linkage of patents to scientific papers. To carry out such studies, we have standardized more than 1 million references to science from the front pages of U.S. and European patents (see Figure 6.1). We put them into a standard "journal, volume,