Navigation Techniques for Dual-Display E-Book Readers Nicholas Chen 1 , Francois Guimbretiere 1 , Morgan Dixon 1 , Cassandra Lewis 1 , Maneesh Agrawala 2 1 University of Maryland 3452 A.V. Williams Building College Park, MD 20742 {nchen, francois, mdixon3}@cs.umd.edu, clewis@umd.edu 2 University of California 635 Soda Hall Berkeley, CA 94720 maneesh@cs.berkeley.edu ABSTRACT Existing e-book readers do not do a good job supporting many reading tasks that people perform, as ethnographers report that when reading, people frequently read from mul- tiple display surfaces. In this paper we present our design of a dual-display e-book reader and explore how it can be used to interact with electronic documents. Our design supports embodied interactions like folding, flipping, and fanning for local/lightweight navigation. We also show how mechanisms like Space Filling Thumbnails can use the increased display space to aid global navigation. Lastly, the detachable faces in our design can facilitate inter-document operations and flexible layout of documents in the work- space. Semi-directed interviews with seven users found that dual-displays have the potential to improve the reading experience by supporting several local navigation tasks better than a single display device. Users also identified many reading tasks for which the device would be valu- able. Users did not find the embodied interface particularly useful when reading in our controlled lab setting, however. Author Keywords E-book, reading, multiple display devices, embodied inter- faces, motion sensing ACM Classification Keywords H5.2. Information interfaces and presentation (e.g., HCI): User Interfaces. INTRODUCTION Although electronic versions of books, papers, and peri- odicals are becoming ubiquitous, people commonly print these documents in order to read, annotate, and interact with them. While laptop and tablet screens are growing in size and resolution, they, unlike paper, consume significant amounts of power, can be difficult to read in sunlight, and their size and weight make them difficult to hold in com- fortable orientations for reading and annotation. In response, various e-books, devices designed specifically for reading electronic documents, have been offered. The most recent of these devices, which include products like the Amazon Kindle [3], use E-Ink [11], one of several bi- stable display technologies that do not require power to maintain an image on the screen and can be read in bright sunlight. Since these devices require far less power than those with LCD displays, they can be made thinner and lighter, resulting in a more mobile platform for reading. However, current e-books provide only a single screen and therefore lack some important affordances of physical reading materials. In particular, embodied navigation in the form of turning, flipping and folding pages is limited. Moreover, the reduced screen real estate of a single-display e-book reader makes it difficult to configure the device to simultaneously show multiple regions of a document. The low power consumption of bi-stable displays make it practical to build portable multi-screen e-books readers. The availability of dual-display readers will be a signifi- cant development since ethnographic studies have consis- Figure 1 - Our prototype e-book reader with faces in the attached, side-by-side configuration (top), and the detached configuration (bottom). Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that cop- ies bear this notice and the full citation on the first page. To copy other- wise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. CHI 2008, April 5–10, 2008, Florence, Italy. Copyright 2008 ACM 978-1-60558-011-1/08/04…$5.00