OK, I agree. I could never give up my Kindle. E-books are great because I never have to worry about running out of something worth reading on trips. And I can start reading that great new book in a minute. Plus, I can make the letters bigger when my eyes are tired. And I can search inside the book for a character's name if I've forgotten who that person was. E-books are taking up a greater and greater percentage of titles sold, and for good reasons.(1)
But there are at least three ways in which print on paper is superior to words on a screen. First, there's the focus vs. distraction factor. When you're reading on your iPad, there's so much temptation to wander away from what you're concentrating on because so many other interesting apps are available at the touch of a button. [With an iPad those apps often come up by accident if you touch the wrong part of the screen!] Research on multitasking and task-switching shows that it not only takes longer to do two things at once than to complete one before starting the other; what is learned is of an inferior quality.(2) To really understand and use what you're reading, you have to integrate it with the paragraph you read a few minutes ago and evaluate it against what you already know. Switching tasks interrupts these processes, ties up your working memory, and leaves a lower level of brainpower to concentrate on the reading task. (See my previous post on multitasking, "Mining Your Inner Moron.")
Second, a printed book's layout is much more likely to promote memory for the content learned. The flexibility of an e-book's display means that the layout you experience will depend on the settings you choose, and if you read the same paragraph twice, it might be in a different location on the screen the second time. In contrast, book publishers pay close attention to how sentences, headings, and illustrations will appear when the book is printed. Not only do these features help you focus on what's important; research on context-dependent learning shows that where a word appears on a page is part of the memory store that helps you remember what you learned.(3) Therefore a printed page is likely to facilitate memory more readily than an electronic screen.
Third, the printed page should be especially advantageous for young children because they are concrete learners. The ability to think abstractly emerges relatively late in development and flourishes in adolescence and beyond.(4) I'm not saying that young children aren't fascinated by audiovisual media—of course they are. But where reading is concerned, they should be especially able to concentrate on books they can hold in their hands and on pages they can turn and even write or scribble on. And they can admire the images for hours without worrying about the screen fading or the battery dying.
For myself, I use my Kindle mainly for novels and other books I read for entertainment. But if I'm reading something I want to learn and apply to my research or my presentations, I want the printed version of a book. I make notes in the margins and use post-it-notes to find my way back crucial sections. Furthermore, I'm reminded of what these books taught me as I see them lying on my desk or in my bookcase. It's true I can make notes and leave bookmarks on my Kindle, but those notes are hidden unless I actively seek them out. For the most part, they remain invisible.
So think about why you're buying a book before you decide what format to buy it in. And don't write off the printing industry just yet.
(1) Kincaid, J. (2011). That Was Fast: Amazon's Kindle Ebook Sales Surpass Print (It Only Took Four Years).
(2) Foerde, K., Knowlton, B., & Poldrack, R. A. (2006). Modulation of competing memory systems by distraction. Proceedings of the National Academy of Sciences. www.pnas.org/cgi/doi/10.1073/pnas.0602659103
(3) Murnane, K., & Phelps, M. P. (1993). A global activation approach to the effect of changes in environmental context on recognition. Journal of Experimental Psychology: Learning, Memory, and Cognition, 19, 882-894.
(4) e.g., Flavell, J. H. (1963). The developmental psychology of Jean Piaget. New York: van Nostrand; Melkman, R., Tversky, B., & Baratz, D. (1981). Developmental trends in the use of perceptual and conceptual attributes in grouping, clustering, and retrieval. Journal of Experimental Child Psychology, 31, 470-486.