This article provides two empirical evaluations of deliberation. Given that scholars of deliberation often argue for its importance without empirical support, we first examine whether there is a "deliberative difference"; if actors engaging in deliberation arrive at different decisions than those who think on their own or "just talk." As we find a general convergence within deliberation scholarship around reasons and inclusion, the second test examines whether these two specific mechanisms are central to deliberation. The first evaluation looks at outcomes (...) within a laboratory setting; the second at videotapes of decision-making processes within this setting. Our results show two things. First, in terms of outcomes, deliberation differs from other forms of interaction. Second, reasons and inclusion are central to the deliberative process. The more reasons provided within each group, the more likely participants were to change their position; similarly, the more inclusive groups were, the more likely participants were to change their position. We conclude by arguing that more work needs to be done, both in evaluating the deliberative difference and in disaggregating deliberation and examining its central explanatory mechanisms. (shrink)