In this paper we develop an analytical framework for studying learning processes in the context of efforts to bring about system innovation by building new networks of actors who are willing to work on a change towards sustainable development. We then use it to evaluate two specific intervention programmes carried out by a self-proclaimed 'system instrument'. The framework integrates elements from the Innovation Systems approach with a social learning perspective. The integrated model proposes essentially that these kinds of systemic instruments can serve to enhance conditions for social learning and that such processes may result in learning effects that contribute to system innovation by combating system imperfections. The empirical findings confirm the assumption that differences in learning can be explained by the existence or absence of conditions for learning. Similarly, the existence or creation of conducive conditions could be linked to the nature and quality of the interventions of the systemic instrument. We conclude that the investigated part of the hypothesised model has not been refuted and seems to have explanatory power. At the same time we propose that further research is needed among others on the relation between learning, challenging system imperfections and system innovation. © 2009 Elsevier Inc. All rights reserved.