Midstream modulation is a form of public engagement with science which benefits from strategic application of science and technology studies (STS) insights accumulated over nearly 20 years. These have been developed from STS researchers’ involvement in practical engagement processes and research with scientists, science funders, policy and other public stakeholders. The strategic aim of this specific method, to develop what is termed second-order reflexivity amongst scientist-technologists, builds upon and advances earlier more general STS work. However this method is focused and (...) structured so as to help generate such reflexivity—over the ‘upstream’ questions which have been identified in other STS research as important public issues for scientific research, development and innovation—amongst practising scientists-technologists in their specialist contexts (public or private, in principle). This is a different focus from virtually all such previous work, and offers novel opportunities for those key broader issues to be opened up. The further development of these promising results depends on some important conditions such as identifying and engaging research funders and other stakeholders like affected publics in similar exercises. Implementing these conditions could connect the productive impacts of midstream modulation with wider public engagement work, including with ‘uninvited’ public engagement with science. It would also generate broader institutional and political changes in the larger networks of institutional actors which constitute contemporary technoscientific innovation and governance processes. All of these various broader dimensions, far beyond the laboratory alone, need to be appropriately open, committed to democratic needs, and reflexive, for the aims of midstream modulation to be achieved, whilst allowing specialists to work as specialists. (shrink)