The “evidence” is in the axis of regulatory planning rhetoric that has clear meaning for scientists. This message not only suggests that politicians widely accept the paradigm shift from “traditional” (less adaptive and responsible) decision-making to science-based decision-making, but also creates new challenges for scientists. Cooperation between policy and science is vital in making policy data available, performing analyses, developing new theories and developing evaluations, as the results of these processes can be considered evidence to support policies. Further important sources of evidence are so-called “best practices” (best ways of working, used by others, to achieve policy objectives) and other lessons learned. However, it is important to note that simply copying a “best practice” does not always guarantee success in a new policy area. Furthermore, political problems and failures can also be considered as evidence but, obviously, as a practice to be avoided. This type of evidence is sometimes more useful for avoiding future errors in policy decisions than knowledge gained from success stories. Science has multiple roles in this process: collecting and analyzing data, developing theories, evaluating outcomes, advising policy makers, and constantly improving methodologies, or in short: providing effective policy-making “technology.” As Sir Karl Popper argues "The only course open to the social sciences is... to address the practical problems of our time with the help of theoretical methods... A social technology is needed which can be tested by social engineering" (Popper 1945 vol ii p210) These two tools (i.e. social theory and social technology) are indispensable for the social sciences to deal with… information about objectives, available policy instruments and the expected compliant behavior of target groups. In an optimal case, the identification of policy measures is based on an ex ante impact assessment (i.e. a preliminary estimate on the feasibility of implementation, the extent to which the expected results can be achieved and the effectiveness of the entire process). Unfortunately, policy makers are under pressure and the choice of regulatory instruments is not always supported by ex ante evaluations. Social sciences can certainly help improve the effectiveness of policy decisions, including risk-based decisions. Although the use of appropriate social science methods can speed up the process of identifying policy measures, time is definitely needed for this research work..