Social studies of science and technology are dominated by action and macro approaches. This has led to a neglect of institutions and institutional arrangements at the meso level, which are important, in particular to the student of technology. The transfer of concepts and methods from social studies of science to technology studies has conserved this lack of concern with the meso level. This article suggests a more critical evaluation of this transfer, along with a review of the now popular assumption (...) of a high degree of similarity between science and technology. Two case studies show how meso-level considerations are important to an understanding of the nature of technological innovation and illustrate the lack of similarity between scientific and technological development. (shrink)