TEDTalks are often praised for its smooth delivery of big ideas, packaged in slick videos with high production quality. But researcher and author Annie Murphy Paul asks, "Do We Actually Learn Anything from TED Talks?" She points to an upcoming study which compared how much people remembered from watching a "fluent" presenter (as many giving TED Talks are) and a "disfluent" one (marked by slouching, lack of eye contact, and choppy delivery). The findings suggest to her that "participants who watched the fluent video thought they would remember much more information than participants who watched the disfluent video--but actually both groups remembered about the same amount."
So the short answer to Paul's question is, yes, but not much more than other forms of videos. What one can't deny, though, is the entertainment and engagement levels in TEDTalks. Murphy also offered five takeaways for video instructors, especially those offering MOOCs, on the effective use of visual presentations and robust conversations.
But behind the flashiness, it's worth remembering that all grand ideas should be taken with a (fat) grain of salt. It's important to distinguish between world-changing inspirations and facts. Recently, the credibility of some TEDx talks have been under question (sometimes quite vehemently), leading the Harvard Business Review to wonder if TED is starting to lose control of its brand and crowd. Perhaps these TEDTalks are just a little too convincing.