3300534
Improving mobile internet usability
Mobile internet technologies, such as WAP, are important for pervasive, anytime, anywhere computing. Although much progress has been made in terms of technological innovation, many of mobile internet systems are difficult to use, lack flexibility and robustness. They give a poor user experience. Evaluation and theoretical analysis of usability combined with innovative design can achieve significant improvements in user performance and satisfaction. Using such multidisciplinary methods explains the negative reactions to WAP, and — more constructively — suggest ways of developing more effective and efficient devices and services.
39410616
Theme issue on interactive mobile information access
This paper introduces this issue on interactive mobile information access. Papers are presented issues relating to a diversity of user groups and environments, with a central theme of accessing information whilst on the move.
7930341
StoryBank: an indian village community digital library
This paper considers information access styles for a community digital library in an Indian village. We present our impressions of the community gathered during a field-study and show how these have influenced the interaction design. The prototype aims to overcome low-textual literacy and lack of computing experience by combining touch-based interaction, engaging visual presentations and drawing on villagers' familiarity with radio listening.
15818085
An evaluation of integrated zooming and scrolling on small screens
Abstract Speed-dependent automatic zooming (SDAZ) has been proposed for standard desktop displays as a means of overcoming problems associated with the navigation of large information spaces. SDAZ combines zooming and panning facilities into a single operation, with the magnitude of both factors dependent on simple user interaction. Previous research indicated dramatic user performance improvements when using the technique for document and map navigation tasks. In this paper, we propose algorithmic extensions to the technique for application on small-screen devices and present a comparative experimental evaluation of user performance with the system and a normative scroll–zoom–pan interface. Users responded positively to the system, particularly in relation to reduced physical navigational workload. However, the reduced screen space reduced the impact of SDAZ in comparison to that reported in previous studies. In fact, for one-dimensional navigation (vertical document navigation) the normative interface out-performed SDAZ. For navigation in two dimensions (map browsing) SDAZ supports more accurate target location, and also produces longer task completion times. Some SDAZ users became lost within the information space and were unable to recover navigational context. We discuss the reasons for these observations and suggest ways in which limitations of SDAZ in the small-screen context may be overcome.
43107545
A Theory of Qualified Types
Abstract This paper describes a general theory of overloading based on a system of qualified types. The central idea is the use of predicates in the type of a term, restricting the scope of universal quantification. A corresponding semantic notion of evidence is introduced and provides a uniform framework for implementing applications of this system, including Haskell style type classes, extensible records and subtyping. Working with qualified types in a simple, implicitly typed, functional language, we extend the Damas-Milner approach to type inference. As a result, we show that the set of all possible typings for a given term can be characterized by a principal type scheme, calculated by a type inference algorithm.
2264317
Web Mash-ups and Patchwork Prototyping: User-driven technological innovation with Web 2.0 and Open Source Software
The recent emergence of Web mash-ups and open source software is driving the development of new practices in software and systems development. In this paper we explore novel practices of user-driven innovation through an examination of several case studies which illustrate how users and developers are exploiting the proliferation of open APIs and open source systems. Developers can rapidly create proofs of concept that are robust enough for actual use by combining preexisting software components. The underlying programming processes involved make use of tried-and-true software development techniques, and may not appear innovative at first. However, the application of these practices and techniques to problem solving by non-programmers shows a high degree of creative innovation, giving rise to new ways of thinking about technology design and production
9085764
Distance Field Compression
This paper compares various techniques for compressing floating point distance fields. Both lossless and lossy techniques are compared against a new lossless technique. The new Vector Transform technique creates a predictor based upon a Vector Distance Transform and its suitability for distance field data sets is reported. The new technique produces a lossless encoding at a third of the file size of entropy encoders, and equivalent to lossy wavelet transforms, where around 75% of the coefficients have been set to zero. The algorithm predicts each voxel value linearly based upon two previous voxels chosen from one of 13 directions which have been previously computed. Those that cannot be predicted are explicitly stored.
18480565
Volumes of expression: artistic modelling and rendering of volume datasets
This paper presents the design and implementation of artistic effects in modelling and rendering of volume datasets. Following different stages of a volume-based graphics pipeline, we examine various properties of volume data, and illustrate how expressive and non-photorealistic effects can be implemented. We demonstrate that the true 3D nature of volume data makes it particularly applicable for this use, allowing the addition of complex effects at the modelling stage as well as during rendering.
7232664
Designing in the dark: the changing user-developer relationship in information systems development
Although user involvement can be problematic for all types of information systems development, the situation has become even more difficult with the recent spread of information technology to senior organizational levels. Better theoretical conceptualization of the dynamic relationship between developers and users in systems development is needed to understand how this relationship shapes, and is shaped by, various constraints. Drawing on Giddens’ work on constraints on human action and interaction, a theoretical conceptualization of the dynamic relationship between developers and executive users is proposed. This is grounded in empirical studies of the executive information systems development process in two organizations. The paper seeks to illustrate the “enabling” properties of the constraints and their ongoing production and reproduction. Such constraints may vary in their malleability and some appear to be relatively resistant to change by developers. Nevertheless, through improvisation and ingenuity, developers can often find ways to overcome them.