This is an interesting piece of research: Is This Why TED Talks Seem So Convincing? that Johnnie Moore points me to in his blog post The popcorn of learning: And here is the original paper: Appearances Can Be Deceiving: Instructor Fluency Increases Perceptions of Learning Without Increasing Actual Learning.
It seems that we over estimate the learning that we gain through a well delivered presentation such as a TED Talk and that in reality we only learn marginally more from a fluent presenter than we do from a boring one who just reads his or her notes.
We need to keep in mind that this was a rather limited study and probably does not represent fully the true picture. Nevertheless, its a significant and somewhat counter-intuitive finding.
One personal reflection though is that people may be over estimating the value as they enjoyed the more fluent presentation.
They were better entertained and felt more stimulated but in reality did not learn a whole lot more than a boring talk.
I see an analogous response when I talk at conferences or workshops about rewards and the fact that the research shows they are ineffective.
The most common response to this - is "But I enjoy being rewarded".
There is a big difference though between enjoying something and it being beneficial or good for you!
Another thought. For me what makes a good talk is not the "learning value" but the "inspirational value".
The value for me in a talk is if it provokes me to go away and take some form of action such as to do more research of my own on the topic or to actually follow through on some of the "new trains of thought" that an inspiring talk has triggered in my head.
Or the conversations it inspires and triggers.
In other words, maybe the real value of a good talk is not in the learning at all.