Social innovation is once more an increasingly popular notion circulating as an apparent means to solve the Grand Challenges of the 21st Century. But this common-sense idea of social innovation is based on a quasi-concept, where processes of innovation are absent. To restore some academic rigour to this important concept, we argue more attention need be paid to these innovation processes in social innovation, and that there is value in using innovation concepts drawn from other areas of innovation studies (disruptive innovation, innovation systems, institutional innovation and socio-technical transitions) in highlighting how small-scale social experiments can ultimately lead to the solution of pressing societal problems. Through a subtle ...