This paper gives an overview of quantitative approaches used to study the science/technology linkage. Our discussion is informed by a number of theoretical approaches that have emerged over the past few years in the area of innovation studies emphasizing the exchange of actors in innovation system and a shift in the division of labour between publicly funded basic research and industrial development of technology. We review the more quantitative literature on efforts made to study such linkage phenomena, to which theorizing in the science policy area has attributed great importance. We then introduce a typology of three approaches to study the science/technology linkage - patent citation, industrial science, and university patenting. For each approach, we shall discuss merits and possible disadvantages. In another step we illustrate them using results from studies of the Finnish innovation system. Finally, we list key limitations of the informetric methods and point to possible hybrid approaches that could remedy some of them.