In this presentation, I will discuss some quantitative and qualitative approaches to examining given fields of research in a national or international context. Specifically, I will argue for a history and sociology of science which combines analyses of social and cognitive structures by using disciplines, specializations and portfolios as units of analysis. I will refer the example of atmospheric science in Canada to illustrate how one can understand the emergence and dynamics of a discipline on a national scale. Similarly, I will propose a new approach to examining research portfolios using the example of avian influenza. In both cases, qualitative research methods should be used to complement and critically assess quantitative data.