Laptops and tablet devices of various sorts are everywhere in college classrooms at this point. Students use them to take notes. Keying is quicker than writing notes longhand, and typed notes are subsequently easier to read. Faculty have two legitimate worries; students are using their devices for activities other than note-taking, and bright screens filled with colorful graphics can distract more than just the student who's not taking notes. The authors referenced below think this is an especially serious problem in large lecture halls where students sit close together and it's all but impossible for the teacher to control who's doing what with their electronic devices.