The practice of deliberation has had its place in participatory governance, in development and other areas, for some time. What do you think of when you hear "deliberation"? Porto Alegre's participatory budgeting? India's Gram Sabhas? Parliament? America Speaks? It's all that - and so much more.
In the most common understanding, deliberation is some form of interpersonal discussion about an issue of public concern. This can range from everyday talk about political issues at, say, the kitchen table, to formalized group discussions that aim at solving a common problem. One definition comes from Delli Carpini, Cook, and Jacobs*, who state that deliberation is "the process through which deliberative democracy occurs," a "specific, important, and idealized category within the broader notion of what we call 'discursive participation'." The category is ideal because, à la Habermas, it requires a range of ideal characteristics to be truly deliberative, first and foremost openness and equality of discourse.