Study author Anne Mangen, an associate prof of literacy studies at Norway's University of Stavanger, says she discovered that reading online may not be as rewarding – or effective – as the printed word. The reasons: The process involves so much physical manipulation of the computer that it interferes with our ability to focus on and appreciate what we're reading; online text moves up and down the screen and lacks physical dimension, robbing us of a feeling of completeness; and multimedia features, such as links to videos and animations, leave little room for imagination, limiting our ability to form our own mental pictures to illustrate what we're reading.