Since the 1990s, public engagement exercises have gained increasing significance for the theory and the practice of technology assessment. In contemporary democratic societies the terms "public engagement" or "public participation" are becoming increasingly popular as a means of approaching certain scarcely manageable issues like the management of risks or the development of emerging technologies.

Partly as a reaction to a perceived loss of trust in governments and expert bodies, participatory approaches have emerged in which the general public as well as stakeholder communities are involved more directly in policy formulation and decision-making. The expected benefits of such enhanced involvement cover: easier and faster decisions by preventing public discontent; greater trust in decision-makers, and decisions through an open and fair procedure; enhanced knowledge on complex issues among decision-makers and citizens through inclusion of lay knowledge and values as well as through mutual learning. Unfortunately, there is little empirical evidence of support for these claims.

Given the increased frequency and the widespread use of participatory procedures in TA it can be said that participatory TA in Europe is a success story. Up to now, however, there has been little systematic empirical evaluation of the role and the impact of pTA processes. There are a few documented evaluations of single pTA exercises involving laypersons as citizens. The unclear political status of pTA and the fact that it often appears to have little influence on decision making have meanwhile led to criticism.

An evaluation of the effects of pTA must take into account that, as it is very well known from knowledge utilization research, it is quite difficult and often impossible to identify the effects of scientific advice on decision-making processes, since such processes are generally influenced by a complex set of interests and rationalities. Thus, far investigation of the role and function of public engagement exercises in the S&T governance as well as their relation to established decision-making processes in representative democratic institutions has not been performed systematically. In this context, important questions of research are for instance:

• What contributions can public engagement exercises make to the quality and to the legitimacy of S&T governance
• In what way are public engagement exercises used by actors in the field of S&T governance
• What role do contextual factors play and should play for the design and the function of public engagement exercises
• What significance do public engagement exercises have and should have within governmental strategies of S&T governance