WSLS in Roanoke, Va., recently replaced a two-year-old newscast that relied heavily on social media with a more traditional program. After a while, the novelty wore off, Diana Marszalek reports. Several local television newscasts are experimenting with interactive social media tools in interesting ways. At KOMU in Columbia, Mo., an anchor uses group video chats, texting, tweets and emails on air. But there may be a limit to how much TV viewers want to participate. Hofstra University journalism professor Bob Papper says as few as 5 percent of TV viewers engage with TV news via social media. “Part of the success of TV news is that it’s the ultimate passive medium,” he says. || Earlier: Anchor creates iPhone newscasts