Experimentation, which initially concerned only the experimental sciences field, is a term now used to describe a great many forms of socio-political practice, for example among governments, activists or artists. This extension of the term’s usage illustrates the influence of imagination in experimental research on contemporary conceptions of politics. It is supporting changes in the patterns of political speech and action that need to be better characterised, as they are occurring at the point where scientific and technical reason meets the transformation of the public sphere.