A survey by the Institute for Social and Political Studies, Rio de Janeiro State University, however, found out that among the mainstream media vehicles, Folha presented the most critical coverage about both main contenders, and that its coverage of candidate José Serra (PSDB) was even more critical than its posture towards Rousseff. The survey, carried out in September and October 2010, shows that, in contrasting positive, negative and neutral reports, Folha held a positive balance of three percent. In the 2006 presidential election, Folha also had "the more balanced and less biased" coverage among daily newspapers, and was the vehicle that expressed more diversified opinions, according to Doxa (the Public Opinion and Political Communication Lab, IUPERJ).