Scientific Dissemination enunciations in the media are form of public discourse that integrates social, cultural, ideological and political aspects related to their spatial and temporal context. With theoretical support of Discourse Analysis the article presents distinct modes of disseminating science to the lay audience found in three magazines disseminating scientific knowledge: the Scientific American Brazil, Pesquisa Fapesp and Superinteressante. The editorial commitment of each one of these magazines to its readers is the basis of the discursive construction. The Scientific American Brazil draws on many sources for its explanations using a technical approach and close proximity to the patterns of science. The Pesquisa FAPESP magazine addresses the themes in their Brazilian context, uses Brazilian scientists as sources and adopts the journalistic reporting genre with exts by specislized journalists. Superinteressante magazine has a has a more distant commitment to science with exts free from using, instead, catch phrases, slang and types of comparison appropriate the language of its audience.
