A.M. Piper and J. Hollan. Tabletop Displays for Small Group Study: Affordances of Paper and Digital Materials. Proceedings of Conference on Human Factors in Computing Systems (CHI) 2009, 1227-1236. 
Abstract
In this paper we compare the affordances of presenting educational material on a tabletop display with presenting the same material using traditional paper handouts. Ten pairs of undergraduate students used digital or paper materials to prepare for exams during four one-hour study sessions over the course of a term. Students studying with the tabletop display solved problems on their own before resorting to answer keys and repeated activities more often than students studying with paper documents. We summarize study activities and discuss the benefits and drawbacks of each medium.