A New User Interface Metaphor for Mobile Personal Technologies

Elisa del Galdo, Paul Gough, Matt Jones, Rob Noble and Philip Stenton

ABSTRACT
As the computer industry advances into the 21st century major changes are taking place in the manner in which users interact with computers. Advances in technology have enabled the miniaturization of components and products. Making truly mobile products a reality. The result is a change in the user's context. Miniaturization allows the creation of products with vast functionality accessed via a very small user interface. Changes in user context and reduction of the user interface make the desktop-like metaphor of the PC inappropriate for the context of mobile use. Currently, these problems have only been addressed by tailoring the existing user interface metaphors and input and output methods. This panel addresses the user interface design challenge that mobile products presents by looking beyond current solutions to the creation of new user interface metaphors and the incorporation and integration of alternative input and output methods.

KEYWORDS:

Mobile personal technologies, user interface metaphors, user interface miniaturisation

INTRODUCTION
Elisa del Galdo: Previously with Digital and an HCI consultant, Elisa del Galdo is a member of the Product Conceptualisation and Prototyping Group at Canon, where she is working on the design of speech and language user interfaces.

As the computer industry advances into the 21st century major changes are taking place in the manner in which users interact with computers. Advances in technology have enabled the miniaturisation of components and products. These small computers are referred to as 'personal technologies' and are truly usable in a mobile fashion. The first and most visible change is the ability to use a product while mobile. This has changed the context in which users work. The user is no longer just transporting the computer to be used at a makeshift or temporary desk. Thus, the desktop-like metaphor that many small devices continue to use is likely to be inappropriate for the context of mobile use.

The second change in interaction is that users have less physical space in which to interact with the computer. This problem is magnified by the gains in technology that yield very small products with diverse and abundant functionality. Many of these products possess a level of functionality that is normally accessed using an interface that is at least four or five times larger. Increased capability in a small product may be seen as a benefit, but designing a small user interface that affords easy access to the product's range of functionality can prove to be very difficult. Often, the result is overly complex and many actually restrict users' access to even commonly used functions.

Many vendors have approached this UI design problem by making adjustments to an existing user interface design originally based on a desktop metaphor. The adjustments include miniaturisation, slight 'look and feel' alterations, and the addition of alternative input or output modalities (e.g., handwriting recognition, voice as data, speech recognition). As newer user interface technology matures and designers develop a better understanding of users' requirements for mobile products (both for tasks and interaction), a new metaphor should emerge. This new 'mobile' metaphor will include multi-modal interaction (i.e., using a combination of input or output methods for a single task), spontaneous interaction, output mechanisms suitable to a small interface all within a metaphor appropriate for the mobile interaction. Addressing the mobile user interface design problem presents many exciting challenges for the HCI community.

Paul Gough: Previously at Xerox, Paul Gough joined Philips in the early eighties. He is the manager of the software research group and is involved in the development of a mobile and personal interfaces research programme.

We believe that the desktop metaphor and direct manipulation interaction style is a deficient combination for mobile users, because of the differences in requirements between mobile and office users. Unlike an office-based user, the mobile user needs to dedicate attention to their task location, and for safety reasons, be aware of their environment. For these reasons, it is difficult to imagine that direct manipulation and a desktop metaphor are the ideal components of a mobile user-interface. Much more appropriate are means of interaction which can be undertaken whilst the user is maintaining awareness of location and environment.

We believe that the user interface will use a mixture of metaphors and interaction styles (e.g., speech gestural, or tactile) to provide access to the available information and functions.

Matt Jones: Senior Lecturer at the School of Computing, Middlesex University. Currently, he is working on an EPSRC funded project(GR/L70028) on handheld web browsing with collaboration from Reuters.

We are at a "defining moment" for mobile personal technologies. Up until recently, PDAs, email 'phones, in car navigation systems and the like have been mainly bought by gadget lovers and early adopters. Soon, though, they will really have to work: people will rely on them to get their jobs done, to help them use their leisure time effectively and, in some cases, to keep them alive. To be successful, mobile interfaces need to have qualities, which the current "desktop" just cannot deliver - focused navigation for task completion, simple and systematic interactions and cross platform independence. The development of new metaphors for the mobile era will have ramifications for interfaces on conventional platforms too -maybe it is time we threw the desktop out of the window altogether.

Rob Noble: a member of the Product Conceptualisation and Prototyping Group at Canon, where he exercises his pet interest in user interface design without being biased by any kind of formal training in HCI.

Today our interaction "language" consists of a vocabulary of mouse-clicks, key presses, text and icons. The transition from desktop computer to mobile computing device makes current input devices awkward to use and output devices more limited. The rate of communication with a small or mobile device is lower, and the int