Propagació de la incertesa en laboratoris d'anàlisi

El document és una guia per al càlcul de la propagació de la incertesa en laboratoris d'anàlisi

Why Do Politicians Tweet? Extremists, Underdogs, and Opposing Parties as Political Tweeters

Why do some politicians actively use social media, while others lag behind? To answer this question, we propose that opposing party politicians, underdogs, and extremists are more likely to become active political tweeters. Research has shown that media attention is generally concentrated on politicians with power; that is, ruling parties and party leaders. We thus hypothesize that politicians marginalized from media attention, namely backbenchers and those from opposing parties, may perceive greater potential benefits from social media. Further, politicians whose ideological positions do not match well with those of major news media (i.e., extremists) may perceive risks in facing tough questions from journalists, as well as the media's gatekeeping process. We thus hypothesize that extremists may perceive greater benefits from using social media, because they can control their message. We tested these hypotheses using data on U.S. Senators’ public communication activities on Twitter and in press releases in 2009–2011 and found strong support