The ‘doing-using-interacting’ (DUI) mode of innovation describes informal innovative activities and it can be juxtaposed with the ‘science-technology-innovation’ (STI) mode based on deliberate research and development. While both modes contribute substantially but differently to technological progress, our empirical understanding of DUI mode innovative activity suffers from the lack of a comprehensive measurement approach. While empirical measurement of the STI mode is well established, empirical indicators for DUI activities are scarce and no consensus has emerged concerning its constituting learning processes. We propose a new measurement conception for innovative activity and based on 81 in-depth interviews with German firms and regional innovation consultants. We derive fifteen categories of DUI mode learning processes and a comprehensive set of 47 indicators comprising both established and new DUI indicators for empirical measurement. This new measurement conception and the respective indicators provide a holistic perspective and their application can be used to increase our understanding of the importance of DUI mode innovative activity, as well as guiding policy-makers.