Research shows that non-classroom related uses of technology can distract you from learning and negatively affect your performance in school:
Froese, Arnold D.; Carpenter, Christina N.; Inman, Denyse A.; Schooley, Jessica R.; Barnes, Rebecca B.; Brecht, Paul W.; Chacon, Jasmin D. (2012). “Effects of Classroom Cell Phone Use on Expected and Actual Learning.” College Student Journal, 46 (2): 323-332.
Other research suggests that having policies about technology in the classroom is seen as a benefit by students:
This is a course on technology, and so use of technology is central to much of what we will do in class. That said, it only counts as class participation if you are using your electronic devices to contribute to the class. You can, for example, use your phone to tweet to the course hashtag (#msp4541) a reaction to in-class discussions/lectures/videos/presentations. Similarly, you may use your laptop to take notes, present group presentations, work on in-class assignments, tweet to the hashtag, or look up articles/videos/facts to contribute to the class discussion. All other uses of your technology will result in a reduced class participation grade. How will I know the difference? If you are on your phone throughout the class but have no tweets posted to the hashtag, are always on your laptop but never contribute, or ask me questions I just answered in class, I’m good at putting two and two together. There are other ways of me guessing what you are up to as well. If you are in class, you are expected to be engaged in the classroom experience.