Content area
Full text
Abstract.
Natural user interfaces want to liberate the user from having to learn new concepts to interact with computers. They do that by taking advantage of our senses and our own knowledge about world in order to build the user interface. Physical user interfaces are a prominent example, where physical objects are enhanced to represent actions or information that the system must exchange with the user. One of the main drawbacks of physical user interfaces is often related with the difficulty to decouple system logic from the specific technology used to build the user interface, especially when multiple environments or scenarios should be supported. This paper presents an abstraction technology for user interaction devices that allows the building of physical user interfaces that are physically and logically decoupled from the system logic.
Keywords: usixml, distributed user interfaces, physical user interfaces, ambient intelligence, ubiquitous computing.
1. Introduction
Since the beginnings of user interaction research, natural user interfaces (UIs) have been one of the most relevant and studied topics. The idea was to liberate the user from having to learn new concepts in order to interact with computers, and take advantage of its own senses and knowledge about objects, physics and the world itself, to interact with computers.
Tangible UIs (Ullmer, 2000) (Patten, 2001), graspable UIs (Fitzmaurice, 1995) and physical UIs (Greenberg, 2001) (Ballagas, 2003) are prominent examples of natural interface research. The main idea shared among them is to rely on physical objects and their intrinsic and known properties, in order to build the user interaction primitives of a digital system. Tangible and graspable UIs, like tabletop UIs (Kaltenbrunner, 2005) (Jordá, 2007), usually allow the user to manipulate some physical objects of different shapes or colours, and use the different manipulation actions to interact with the user. On the other hand, physical UIs rely much more on ad-hoc physical objects, or even on enhanced everyday objects, to provide physical representations of the interactive capabilities of the system.
The main idea behind physical UIs is to take advantage of physical objects to bridge the gap between the users and the state of a digital system. These objects are controlled by the digital system and provide a physical representation of actions or outputs that the system must...