Deliberation has become, in the words of one scholar, “the most active area of political theory in its entirety” (Dryzek 2007, 237). Our exploration of the relationship between experiments and deliberation thus begins with normative theory as its starting point. Experiments can yield unique insights into the conditions under which the expectations of deliberative theorists are likely to be approximated, as well as the conditions under which theorists' expectations fall short. Done well, experiments demand an increased level of conceptual precision from researchers of all kinds who are interested in deliberative outcomes. However, perhaps most important, experiments can shed greater scholarly light on the complex and sometimes conflicting mechanisms that may drive the outcomes of various deliberative processes. In other words, experiments allow researchers to better understand the extent to which, the ways in which, and under what circumstances it is actually deliberation that drives the outcomes deliberative theorists expect.

Our strategy for this chapter is to highlight the strengths of experiments that have already been completed and to point to some aspects of the research that need further improvement and development. We aim to discuss what experiments can do that other forms of empirical research cannot and what experiments need to do in light of the normative theory.