Comparing Table Views for Small Devices Carolyn Watters Faculty of Computer Science Dalhousie University Halifax, Nova Scotia, Canada, B3H 1W5 Tel: 1-(902)494-6721 watters@cs.dal.ca Rui Zhang Faculty of Computer Science Dalhousie University Halifax, Nova Scotia, Canada, B3H 1W5 Tel: 1-(902)444-9466 rzhang@cs.dal.ca Jack Duffy School of Business Administration Dalhousie University Halifax, Nova Scotia, Canada, B3H 1Z5 Tel: 1-(902)494-1838 Jack.Duffy@dal.ca ABSTRACT Users expect access to Web data from a wide range of devices, both wired and wireless. Many users switch back and forth between devices, including laptops and Personal Data Assistants (PDAs), and expect to be able to continue working with that data. The goal of this research is to inform the design of applications that support the user by providing reasonably seamless migration of Web data among internet-compatible devices with minimal loss of effectiveness and efficiency. Earlier studies concentrated on the dynamic transformation of text content, lists, and forms embedded in web pages for access on a range of devices from desktop to handheld. This study focuses on the transformation of large tables onto small mobile devices. In this paper we report on the results of two user studies that examine effectiveness and efficiency of three basic models for the display of tables, originally intended for use on larger screen, on PDA size screens for both simple and complex tasks. Categories and Subject Descriptors H.5.2 Information Interfaces and Presentation; User Interfaces; Screen Design General Terms Documentation, Performance, Design, Experimentation, Human Factors. Keywords PDA, small screen, handheld device, auto-transformation, Focus + Context, Tables. 1. INTRODUCTION The rapid acceptance of handheld Internet-compatible devices has increased the requirement to access information efficiently and effectively across a variety devices. Users in many fields, such as business, medicine and education rely on using both full size and small mobile devices for information tasks. Usability factors are critical for users of data on small screens and need to be considered carefully for objects that are expected to migrate from device to device, especially when the screen size of the target devices varies significantly. In this paper we examine tables on small screen. Consider, by way of example, the needs of a user who accesses a large table of data on his or her laptop or desktop and subsequently needs to refer to that data on a PDA or a user who is using a PDA while collaborating with someone who is using the same table on a large screen. We can think of examples in drug interaction tables, for example, where the pharmacist and the physician are better served by common view of the table under discussion. Errors and frustration may result from large variations in the information model for access on different devices. Reorganization of previously seen data increases the user’s cognitive overhead as they need to consciously remap their model of the data and this may increase errors in locating data and in the comprehension of data [1]. To this end, we propose that users would benefit from a consistent mental model of the information that is independent at some level, from the actual device in use so that they can migrate between devices with minimal content and comprehension loss. There may be tradeoffs, however, between the maintenance of a consistent mental model and ease of use on individual devices. In this paper, we focus on the display and manipulation of existing tables, such as those found in web pages, on PDAs. That is, we are concerned with the target representation of such tables rather than the complexities of the algorithm used to perform the transformation. 2. RELATED WORK Tables are inherently two-dimensional structures, where the spatial layout is an essential component of the semantics. The contextual component of tables, such as title and column headings, particularly on small screens, has been shown in earlier work to have a significant effect on both effectiveness and efficiency of complex task and on the small screen devices [2]. 2.1 Display Problems on Small Screen Devices Any design for use on the small screen must be informed by consideration of those characteristics that have been shown to affect the performance of users on small screens. An early study by Reseil and Shneiderman [3] showed that the smaller screen size does slow down the reading time, while a study by Jones et al. [4] found that the smaller screen size impedes search task 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 copies bear this notice and the full citation on the first page. To copy otherwise, or republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. SAC’05, March 13-17, 2005, Santa Fe, New Mexico, USA. Copyright 2005 ACM 1-58113-964-0/05/0003…$5.00. 975 2005 ACM Symposium on Applied Computing