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Abstract

Deliberative (and educational) theories typically predict knowledge gains will be enhanced by information structure and discussion. In two studies, we experimentally manipulated key features of deliberative public engagement (information, instructions, and discussion) and measured impacts on cognitive-affective engagement and knowledge about nanotechnology. We also examined the direct and moderating impacts of individual differences in need for cognition and gender. Findings indicated little impact of information (organized by topic or by pro-con relevance). Instructions (prompts to think critically) decreased engagement in Study 1, and increased it in Study 2, but did not impact post-knowledge. Group discussion had strong positive benefits for self-reported cognitive-affective engagement across studies. Also, for some types of engagement, effects were more positive for women than men. When predicting knowledge, there also was some evidence that discussion was more positive for women than men. Finally, need for cognition positively predicted engagement and knowledge gains, but rarely moderated the experimental effects. Given these mixed results, future research should continue to test theoretical assumptions about the effects of specific deliberative design features.