Since the first notion of screen reading, many studies have been performed to discern any differences between reading off of an electronic device and reading off of a paper. In a 2013 study, a group of 72 high school students in Norway were randomly assigned into one of two groups: one that read using PDF files on a computer and one that used standard paper. The students were put through various tests involving reading-comprehension and vocabulary. The results indicated that those who read using the PDF files performed much worse than those reading off of a paper. A conclusion was reached that certain aspects of screen reading, such as scrolling, can impede comprehension.
