Author: Ildeu Moreira, PCST, Brazil

The use of social networks for PCST activities has grown considerably in the last years. Little is known about the usage profile of these tools, and major challenges are to expand their scope, to increase the involvement of the participants and how to measure their impacts. In this paper we present an analysis of the Facebook pages used for two major events in Brazil. Rio+20, the United Nations Conference on Sustainable Development took place in Rio de Janeiro, in June 2012, twenty years after the landmark 1992 Earth Summit in Rio. Many PCST activities were organized throughout the week of the event in Rio. A large warehouse in the port was used for these activities, which encompassed exhibitions, science fairs, debates, etc. They reached an estimated audience of 100,000 people, of which the majority was made up of children and young people. A Facebook page was used to report on the event and present topics related to science and environmental issues. A second experience occurred with the FB page of the International Year of Light in 2015 in Brazil. In this case, with about 3,000 participants, the page has had a growing impact with a large number of threads being tanned and shared. In this communication we analyze the profile of the participants of this community and their involvement with the FB page. Emphasis will be given to posts related to: (i) general information on events, competitions, etc; (ii) history of science topics on light; (iii) new researches about light and its applications; (iv) history of
S&T in Brazil. On each of these themes we will analyze the content posted, the degree of involvement of the participants, and comments and questions made by them.