Regional development policies to foster innovation and competitiveness have evolved towards a ‘soft’ focus on facilitating relationships of cooperation. This is demonstrated by the popularity of network and cluster policies. However, the development of these policies poses particular challenges since there is insufficient understanding of the factors in the social structure that underpin networking behaviour and network outcomes. The analysis of this social context provides an important base for policy learning and therefore for the development of networking policies. The paper makes both a theoretical contribution (in establishing the framework) and a methodological contribution (in exploring its implementation in an ongoing policy process). The case studied is that of the Basque aeronautics cluster, a medium-sized cluster with 35 members founded in 1997 within the Basque Country (Spain) cluster policy, one of the longest-running cluster policies in Europe. The participatory design carried out in the application of the theoretical framework to the case study enabled a deeper appreciation of the different realities and behaviour of targeted firms and supported strategies to improve policy effectiveness.