Participatory technology assessment often holds sessions for experts to inform laypersons about scientific controversies. However, few studies examine how these laypersons perceive experts and make policy recommendations. The purpose of this study was to examine interactions between experts and laypersons in two consensus conferences in Taiwan to find illuminating illustrations. Quantitative and qualitative methods were employed to understand the cases. We found that in each of the two consensus conferences, on average the level of laypersons' science literacy in terms of content was improved and their attitudes toward scientific controversies changed. Expert lectures were perceived as the most important element in influencing participants' knowledge learning and attitude changes. However, in exchanging views with experts, laypersons could not only identify biases, normative positions, and personal preferences in experts' seemingly objective talks, but could also raise reflective, worthy viewpoints that were not articulated by the experts. Implications of the findings to research and practices of participatory technology assessment were discussed.
