There has been abundant research on the relationships between different actors in an innovation system, particularly when cultural differences and divergent organisational practices pose a barrier to collaboration and knowledge exchange among different actors. In this paper we focus on situations in which actors lack awareness of what themselves and other relevant actors in the system can offer or require. To respond to this situation, policy practitioners in different contexts have devised remarkably similar responses to the problem of developing linkages when actors in the system do not perceive a need for these to exist. We have developed the concept of "interface structures" to refer to this type of organisations. The paper discusses this notion, relates it to similar concepts in the literature, and concludes that they constitute a different type of organisational approach. They aim to generate changes in the attitudes and expectations of actors, and when successful they will lead to improved linkages among the actors of an innovation system.