【正文】 news they need to know. [1] Some 44% of online news users get news at least a few times a week through s, automatic updates or posts from social working sites. In 2021, Twitter39。 worth on Twitter. We also have analyzed a year of the most viewed newsrelated videos on YouTube. Several clear trends emerge. Most broadly, the stories and issues that gain traction in social media differ substantially from those that lead in the mainstream press. But they also differ greatly from each other. Of the 29 weeks that we tracked all three social platforms, blogs, Twitter and YouTube shared the same top story just once. That was the week of June 1519, when the protests that followed the Iranian elections led on all three. Each social media platform also seems to have its own personality and function. In the year studied, bloggers gravitated toward stories that elicited emotion, concerned individual or group rights or triggered ideological passion. Often these were stories that people could personalize and then share in the social forum – at times in highly partisan language. And unlike in some other types of media, the partisanship here does not lean strongly to one side or the other. Even on stories like the Tea Party protests, Sarah Palin and public support for Obama both conservative and liberal voices e through strongly. On Twitter, by contrast, technology is a major focus – with a heavy prominence on Twitter itself – while politics plays a much smaller role. The mission is primarily about passing along important – often breaking – information in a way that unifies or assumes shared values within the Twitter the breaking news that trumped all else across Twitter in 2021 focused on the protests following the Iranian election. It led as the top news story on Twitter for seven weeks in a row – a feat not reached by any other news story on any of the platforms studied. YouTube has still other characteristics that set it apart. Here, users don39。t stay long on any one story. On blogs, 53% of the lead stories in a given week stay on the list no more than three days. On Twitter that is true of 72% of lead stories, and more than half (52%) are on the list for just 24 hours. And most of those top weekly stories differ dramatically from what is receiving attention in the traditional press. Blogs overlap more than Twitter, but even there only about a quarter of the top stories in any given week were the same as in the “MSM.” Instead, social media tend to home in on stories that get much less attention in the mainstream press. And there is little evidence, at least at this point, of the traditional press then picking up on those stories in response. Across the entire year studied, just one particular story or event – the controversy over s relating to global research that came to be known as “ Climategate ” – became a major item in the blogosphere and then, a week later , gaining more traction in traditional media. These are some conclusions