According to a recent series of experiments conducted at Princeton University and the University of California, Los Angeles, it was discovered (via The New York Times) that students using laptops to take notes during class were found to have a worse understanding of the lecture that was, versus those that didn’t. This was measured using a standardized test.
Based on their findings in the experiment, researchers hypothesized that the efficiency in note-taking meant that students could keep typing as the lecturer spoke without pause, which meant that the words of the lecturer might not have a chance for substantive processing in their brains.
They found that the notes taken by students using laptops read more like transcripts of the lecture, versus handwritten notes which were more succinct. In another study that explored the idea of using laptops in class conducted by researchers at York University and McMaster University (via The Verge) saw students asked to search for something unrelated on their laptops during class.
Unsurprisingly it was found that these students did not remember much of the lecture, and what was surprising was how it also affected other students that were seated around them as well.