Such tweets are difficult to comprehend, lack context without a detailed explanation, and might be detrimental to the persons who are tweeting because they aren't paying attention to the lecture.
I have never had such a response to a blog post before. Live tweeters were highly indignant that I should question what they are certain is the greatest marvel in medical education since the invention of PowerPoint.
I said it took a minute to compose and type a tweet, and many claimed they can do it much faster. Others also said that they use their tweets as notes for later reference.
A twitter colleague, Dr. John Mandrola (@drjohnm), unknowingly stepped into the conversation by posting a link to an article [link fixed 6/8/14] in The New Yorker about college teachers proposing to ban laptops in their classrooms.
It referenced a 2003 study from Cornell "wherein half of a class was allowed unfettered access to their computers during a lecture while the other half was asked to keep their laptops closed."
"The experiment showed that, regardless of the kind or duration of the computer use, the disconnected students performed better on a post-lecture quiz. The message of the study aligns pretty well with the evidence that multitasking degrades task performance across the board."
A New York Times piece about handwriting said, "For adults, typing may be a fast and efficient alternative to longhand, but that very efficiency may diminish our ability to process new information."
It cited a study showing "that in both laboratory settings and real-world classrooms, students learn better when they take notes by hand than when they type on a keyboard. Contrary to earlier studies attributing the difference to the distracting effects of computers, the new research suggests that writing by hand allows the student to process a lecture’s contents and reframe it—a process of reflection and manipulation that can lead to better understanding and memory encoding."
The New Yorker article concluded, "Institutions should certainly enable faculty to experiment with new technology, but should also approach all potential classroom intruders with a healthy dose of skepticism, and resist the impulse to always implement the new, trendy thing out of our fear of being left behind." [Emphasis mine.]