Because we have the ability to navigate paper resources wordlessly. We engage with them sensorily, using touch and even smell to sort and track them. By connecting with books in this way, we can rapidly reference multiple works. The brain makes geospatial connections with the printed volume regarding progress and the location of memorable passages based on the feel of the book in the hand. We remember where something was in the book. Using this tactile information we can swiftly and deftly gain understanding of the architecture of any printed resource.

Having both print and digital at one’s disposal is a luxury that should be enjoyed as often as possible. While the mind is excellent at encoding sensory cues into our understanding of a printed book, the portability and searchable text of an electronic resource adds substantially to its overall usefulness. Not only can specific passages be found painlessly, but a meta analysis of key terms can lead to a better understanding of the scope of the work.

Interesting article on print vs. paper:

http://www.washingtonpost.com/posteverything/wp/2015/01/12/the-case-against-kindle-why-reading-paper-books-is-better-for-your-mind-and-body/?tid=trending_strip_6