Recent troubles experienced in Japanese nuclear facilities resulted in degradation of public trust in nuclear industry and experts in the domain. Governmental organizations and electric utility companies have been conducting various efforts such as public hearing and information disclosure with the aim of recovering the degraded trust.

But these efforts were mostly in one-way communication scheme from decision-makers to public, and thus by no means effective enough to establish public trust in nuclear experts. The similar situation, i.e. lack of trust, has been confirmed in other advanced science and technology domains such as bio-engineering and nana-technology.

The final goal of this study is to find out an effective scheme of mutual communication about science and technology for better risk understanding and decision-making based on realistic and rational discussions. As the first step toward the goal, recovery of public trust in domain expert has been pursued in this study.

A series of dialogue forums has been launched in two municipalities where nuclear facilities are sited. The scheme of dialogue forum has been employed as a reference model to a methodology for improved risk communication and consensus formation.

Examination of verbal statements expressed by participated citizens indicated that their trust in the experts has been improved significantly through the dialogue forums. The local members of both forums showed a marked change of attitude from distrust to trust in the experts. In addition, the similar change was observed in the attitude of experts as well. Therefore, the change was reciprocal rather than one-sided.

Most of public participants felt that repetitive and mutual communication are important to establishment of mutual trust. The same recognition has been shared by the experts as well.

The changes of opinions and attitude have been carefully analyzed and the results are summarized as follows. In public participants, the opinions showed a significant shift from emotional to practical, while the attitude showed a marked tendency from passive to proactive. On the other hand, in the expert participants, the opinions showed a significant shift from expert-based to public-based risk recognition, while the attitude showed a clear tendency from teaching oriented to co-learning oriented thinking.

These changes of opinions and attitude are generated as co-evolving rather than single process. It can be stressed that this type of changes is most important for reestablishment of mutual trust. In this regard “The Model of Co-evolution of Risk Recognition” has been proposed to develop the new scheme of science communication.