Context-aware Retrieval: Exploring a New Environment for Information Retrieval and Information Filtering

The opportunities for context-aware computing are fast expanding. Computing systems can be made aware of their environment by monitoring attributes such as their current location, the current time, the weather, or nearby equipment and users. Context-aware computing often involves retrieval of information: it introduces a new aspect to technologies for information delivery; currently these technologies are based mainly on contemporary approaches to information retrieval and information filtering. In this paper, we consider how the closely related, but distinct, topics of information retrieval and information filtering relate to context-aware retrieval. Our thesis is that context-aware retrieval is as yet a sparsely researched and sparsely understood area, and we aim in this paper to make a start towards remedying this.     

Understanding and Using Context

Context is a poorly used source of information in our computing environments. As a result, we have an impoverished understanding of what context is and how it can be used. In this paper, we provide an operational definition of context and discuss the different ways in which context can be used by context-aware applications. We also present the Context Toolkit, an architecture that supports the building of these context-aware applications. We discuss the features and abstractions in the toolkit that make the task of building applications easier. Finally, we introduce a new abstraction, a situation which we believe will provide additional support to application designers.     

Building Distributed Context-Aware Applications

Context-aware applications gather information from sensors about their users and operating environment. Sensor handling is a complicated issue that makes it hard and time-consuming to develop context-aware applications. This paper shows how dynamic discovery protocols can be employed to deal with the physical distribution of sensors and the need to share sensors between many applications. We report on our experiences from building a position-aware application using the dynamic discovery protocol that is part of the Jini software infrastructure for distributed systems.     

Metaphors and Context-Aware Information Access

Metaphors are often used to provide the user with a mental model to ease the use of computers. An example of such a metaphor is the commonly used “Desktop Metaphor”. Metaphors also can be used to ease context-aware information access for the users of mobile information systems. In this paper we present a taxonomy that allows the categorisation of such metaphors. Furthermore, we give an overview of existing metaphors and their implementations. After introducing some new metaphors we conclude our considerations with a classification of new and existing metaphors using our taxonomy.     

An Evaluation of the Potential of Task Analysis in the Evolution of Interactive Work Systems

Developed forms of task analysis allow designers to focus on both utility and usability issues in the development of interactive work systems. The models they generate represent aspects of the human, computer and domain elements of an interactive work system. Many interactive work systems are embedded in an organisational context. Pressure for changes are present in this context and provide impetus to stakeholders to change work tasks and the supporting tools. Interactive work systems also provide evolutionary pressures of their own, changing the very task they were designed to support. One approach to coping with change has been to evolve interactive work systems. Currently none of these techniques place focus on the performance of tasks as central, and consideration of usability is minimal. However, an evolutionary design approach forces an evolutionary experience upon users, and we cannot be sure whether this approach enhances the user’s experience or degrades their performance. Given the strength of task analysis it is likely that it will be applied within evolutionary contexts. Yet, little work has been undertaken to examine whether its role will, or could be different. We ask how we can move task analysis towards being used in a principled manner in the evolution of interactive work systems. This paper examines a number of features of the approach called task knowledge structures that may be useful in evolving interactive work systems. We look at tasks and their representativeness, roles, goals, objects (their attributes, relationships, typicality and centrality) and actions. We present a developing framework for examining other task analysis approaches for their utility in supporting interactive work systems evolution. Finally, we discuss future work within the area of applying task analysis in the evolution of interactive work systems.     

Supporting information access in a hospital ward by a context-aware mobile electronic patient record

Context-awareness holds promise for improving the utility of software products. Context-aware mobile systems encompass the ability to automatically discover and react to changes in an environment. Most contemporary context-aware mobile systems aim to support users in private situations, for example, as tourist guides. Thus, we still lack an understanding of the impact of context-awareness in professional work situations. In this paper, we explore context-awareness for mobile electronic patient records through the design of a context-aware mobile prototype called MobileWard. The aim of MobileWard is to support nurses in conducting morning procedures in a hospital ward. MobileWard is context-aware as it is able to discover and react autonomously according to changes in the environment and since it integrates the ability to provide information and services to the user where the relevancy depends on the user’s task. We evaluate MobileWard in two usability evaluations to assess the usefulness of the system and we find that context-awareness holds some promising opportunities, but that it also introduces some potential interaction problems when users are mobile and working in a professional environment. Implications and limitations of the proposed solution are further discussed.     

Modelling and Adapting to Context

One of the hardest points in context-aware applications is deciding what reactions a system has to a certain context. In this paper, we introduce an architecture used in two context-aware museum guides. We discuss how the context is modelled and we briefly present a rule-based mechanism to trigger system actions. A rule-based system offers the flexibility required to be context-sensitive in the broadest sense since many context features can be considered and evaluated at the same time. This architecture is very flexible and easily supports a fast prototyping approach.     

Representations in Human–Computer Systems Development

When system developers design a computer system (or other information artefact), they must inevitably make judgements as to how to abstract the domain and how to represent this abstraction in their designs. Over the years human–computer interaction, or more generally information systems design, has had a history of developing competing methods and models for both the process and products of its development. Various paradigms have been suggested, often trying to keep pace with the changing nature of the design problem; from batch processing to interactive systems to work situations and most recently to designing for household environments. It appears timely, then, to review the nature of the design problem that faces the developers of human–computer systems and to consider some of the impact that different representations and different conceptualisations may have on their activities. Green (1998) has suggested that a single model of developing human–computer systems is not desirable, instead arguing for a number of limited theories each of which provides a useful perspective. The aim of this paper is to place competing methods side by side in order to see their strengths and weaknesses more clearly. The central tenet of the paper is that different views of both the human–computer system design process and the different abstractions, or models, that are produced during the design process have varying degrees of utility for designers. It is unlikely that any single method or modelling approach will be optimal in all circumstances. Designers need to be aware of the range of views that exist and of the impact that taking a particular approach may have on the design solution.     

Modelling both the Context and the User

Research into context-aware computing risks losing sight of the user. This paper discusses how different types of information about a user, ranging from information about the current context to information about the user’s long-term properties, can simultaneously be relevant to a given adaptation decision. Pointers are given to two areas of research that can help with the integration of a broader range of information into context-aware systems: research on user-adaptive systems and on decision-theoretic methods.     

Interactive authoring of multimedia documents in a constraint-based authoring system

As multimedia applications spread widely, it is crucial for programming and design support systems to handle “time” in multimedia documents effectively and flexibly. This paper presents a set of interactive system support tools for designing and maintaining the temporal behavior of multimedia documents. The tool set provides mechanisms for anomaly detection, temporal query processing, and interactive scheduling. It is based on a fast incremental constraint solver we have developed, which can be adapted by any constraint-based system. The incremental constraint solver provides immediate feedback to the user, supporting a highly interactive design process. Combined with existing optimal layout generation mechanisms proposed in the literature, our tools effectively utilize the flexibility provided by constraint-based systems.     

People, Information Systems and Change

Information systems are the glue between people and computers. Both the social and business environments are in a continual, some might say chaotic, state of change while computer hardware continues to double its performance about every 18 months. This presents a major challenge for information system developers.  The term user-friendly is an old one, but one which has come to take on a multitude of meanings. However, in today’s context we might well take a user-friendly system to be one where the technology fits the user’s cognitive models of the activity in hand. This article looks at the relationship between information systems and the changing demands of their users as the underlying theme for the current issue of Cognition, Technology and Work.  People, both as individuals and organisations, change. The functionalist viewpoint, which attempts to freeze and inhibit such change, has failed systems developers on numerous occasions. Responding to, and building on, change in the social environment is still a significant research issue for information systems specialists who need to be able to create living information systems.     

Practical volumetric sculpting

sculpture metaphor for rapid shape prototyping. The sculpted shape is the isosurface of a scalar field spatially sampled. The user can deposit material wherever he desires in space and then iteratively refine it, using a tool to add, remove, paint, or smooth some material. We allow the use of free-form tools that can be designed inside the application. We also propose a technique to mimic local deformations so that we can use the tool as a stamp to make imprints on an existing shape. We focus on the rendering quality too, exploiting lighting variations and environment textures that simulate good-quality highlights on the surface. Both greatly enhance the shape estimation, which is a crucial step in this iterative design process, in our opinion. The use of stereo also greatly eases the understanding of spatial relationships. Our current implementation is based on GLUT and can run the application both on Unix-based systems, such as Irix and Linux, and on Windows systems. We obtain interactive response times, strongly related to the size of the tool. The performance issues and limitations are discussed.     

Assessing continuity and compatibility in augmented reality systems

Integrating computer-based information into the real world of the user is becoming a crucial challenge for the designers of interactive systems. The Augmented Reality (AR) paradigm illustrates this trend. Information is provided by an AR system to facilitate or to enrich the natural way in which the user interacts with the real environment. We focus on the output of such systems and, in particular, on the smooth integration of additional information in the real environment of the user. We characterize the integration of the computer-provided entities with the real ones using two new properties: compatibility and continuity. After defining the two properties, we provide factors and an analytical method needed for assessing them. We also empirically study the two properties to highlight their impact on interaction. The CASPER system, developed in our teams, is used to illustrate the discussion. Published online: 14 May 2002     

A Context/Communication Information Agent

We are developing a Context/Communication Information Agent (CIA), an autonomous software agent that proactively searches for the right information at the right time. Our goal is to design and evaluate a system that leverages what people naturally do, using this knowledge to retrieve information, and presenting it with a minimal cost of disruption to the users. In this paper, we describe the results a low-fidelity prototype performed in a meeting situation, the design space for such an application, and our plans for continued investigation.     

Transformation and exchange of multimedia objects in distributed multimedia systems

One of the challenges in the design of a distributed multimedia system is devising suitable specification models for various schemas in different levels of the system. Another important research issue is the integration and synchronization of heterogeneous multimedia objects. In this paper, we present our models for multimedia schemas and transformation algorithms. They transform high-level multimedia objects into schemas that can be used to support the presentation and communication of the multimedia objects. A key module in the system is the Object Exchange Manager (OEM). In this paper, we present the design and implementation of the OEM module, and discuss in detail the interaction between the OEM and other modules in a distributed multimedia system.     

Embodiments, avatars, clones and agents for multi-user, multi-sensory virtual worlds

This paper explores the issue of user embodiment within collaborative virtual environments. By user embodiment we mean the provision of users with appropriate body images so as to represent them to others and also to themselves. By collaborative virtual environments we mean multi-user virtual reality systems which explicitly support cooperative work (although we argue that the results of our exploration may also be applied to other kinds of collaborative system). The main part of the paper identifies a list of embodiment design issues grouped by the general themes of personal representation, conveying activity, embodiment in heterogeneous systems, embodiment of agents, and ethical issues. These issues are illustrated with examples from our own DIVE and MASSIVE collaborative virtual environments. The paper also uses this set of issues as an analytical framework for comparing a number of other communication technologies.     

Socio-Technical and Soft Approaches to Information Requirements Elicitation in the Post-Methodology Era

The contributors to this special issue focus on socio-technical and soft approaches to information requirements elicitation and systems development. They represent a growing body of research and practice in this field. This review presents an overview and analysis of the salient themes within the papers encompassing their common underlying framework, the methodologies and tools and techniques presented, the organisational situations in which they are deployed and the issues they seek to address. It will be argued in the review that the contributions to this special edition exemplify the ‘post-methodological era’ and the ‘contingency approaches’ from which it is formed.     

Context-Aware Mixed Reality: A Learning-Based Framework for Semantic-Level Interaction

Mixed reality (MR) is a powerful interactive technology for new types of user experience. We present a semantic-based interactive MR framework that is beyond current geometry-based approaches, offering a step change in generating high-level context-aware interactions. Our key insight is that by building semantic understanding in MR, we can develop a system that not only greatly enhances user experience through object-specific behaviours, but also it paves the way for solving complex interaction design challenges. In this paper, our proposed framework generates semantic properties of the real-world environment through a dense scene reconstruction and deep image understanding scheme. We demonstrate our approach by developing a material-aware prototype system for context-aware physical interactions between the real and virtual objects. Quantitative and qualitative evaluation results show that the framework delivers accurate and consistent semantic information in an interactive MR environment, providing effective real-time semantic-level interactions.