Research by Dr. Jakob Nielsen of the Nielsen Norman Group found that it will take you longer to read a page on an electronic device compared to the printed page:
It will take you longer to read a book on an iPad or Kindle compared to the printed page, according to a recent study. Dr. Jakob Nielsen of the Nielsen Norman Group--a product development consultancy that is not associated with Nielsen, the metrics company--compared the reading times of 24 users on the Kindle 2, an iPad using the iBooks application, a PC monitor and good old fashioned paper. The study found that reading on an electronic tablet was up to 10.7 percent slower than reading a printed book. Despite the slower reading times, Nielsen found that users preferred reading books on a tablet device compared to the paper book. The PC monitor, meanwhile, was universally hated as a reading platform among all test subjects.
Nielsen's findings were based on the performance of 24 users who "like reading and frequently read books." The subjects each read different short stories by Ernest Hemingway on all four platforms, and were measured for their reading speeds and story comprehension. Overall, it took each user an average of 17 minutes and 20 seconds to read a story regardless of the platform and comprehension levels were virtually identical on all four reading formats.
However, Nielsen says the printed book was the clear winner in terms of speed. Users were reading 6.2 percent slower on an iPad compared to paper, and 10.7 percent slower on the Kindle 2. Nielsen did not provide any statistics on the reading time for the PC monitor.