Exploring Context-aware Information Push

Despite much interest over recent years in the area of context-aware computing, there are still a number of significant gaps in our understanding of the HCI issues associated with such systems. One particular issue that remains relatively unexplored is how to design around the apparently conflicting goals of adapting to changes in context while at the same time adhering to the principle of predictability. In this paper, we describe our exploration into this issue through two alternative designs of an interactive context-aware tourist guide. One original design was based around information pull, i.e. the emphasis is on the user to decide when context-aware information is presented. Our second design incorporates the notion of information push whereby the actual presentation of context-aware information is triggered by contextual events, e.g. changes in the user’s location or changes to the opening times of attractions. Through the evaluation of these alternative designs we hope to gain a better understanding of the usability implications relating to push vs. pull in both this specific domain and in interactive context-aware systems in general.     

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.     

TRIP: A Low-Cost Vision-Based Location System for Ubiquitous Computing

Sentient Computing provides computers with perception so that they can react and provide assistance to user activities. Physical spaces are made sentient when they are wired with networks of sensors capturing context data, which is communicated to computing devices spread through the environment. These devices interpret the information provided and react by performing the actions expected by the user. Among the types of context information provided by sensors, location has proven to be especially useful. Since location is an important context that changes whenever the user moves, a reliable location-tracking system is critical to many sentient applications. However, the sensor technologies used in indoor location tracking are expensive and complex to deploy, configure and maintain. These factors have prevented a wider adoption of Sentient Computing in our living and working spaces. This paper presents TRIP, a low-cost and easily deployable vision-based sensor technology addressing these issues. TRIP employs off-the-shelf hardware (low-cost CCD cameras and PCs) and printable 2-D circular markers for entity identification and location. The usability of TRIP is illustrated through the implementation of several sentient applications.     

Composite Device Computing Environment: A Framework for Situated Interaction Using Small Screen Devices

Contemporary small screen devices are used as personal companion or communication devices. However, their physical dimensions constrain the processing, communication and user interface capabilities. Thus, rich content presentation and diverse service access via small screen appliances is limited accordingly. This paper introduces the Composite Device Computing Environment (CDCE) that provides a framework for dynamically detecting and utilising surrounding computing resources to overcome the small screen device limitations. CDCE includes the communication infrastructure in addition to supporting alternative models for interactivity between small screen clients and surrounding computing resources.     

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.     

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.     

Modelling and analysing a distributed dynamic channel allocation algorithm for mobile computing using high-level net methods

A distributed dynamic channel allocation algorithm has been proposed in [11]. In this paper the algorithm is modelled using predicate/transition nets. The same model can be used for any number of cell and channel configurations. The Maria reachability analyser has been used to analyse the protocol for some configurations. These are deadlock-free and are shown to satisfy the requirement that the same channel is never allocated to two neighbouring cells. The suitability of high-level nets for the modelling and analysis of distributed algorithms is discussed. Published online: 24 August 2001     

Information and Communication Technologies: Perspectives and their Impact on Society

The most fundamental changes of information exchange and communication in society today have been caused by the fast and thorough penetration of all facets of life through networked computers and mobile phones, which will both soon merge with our traditional TV. In this report, these developments will be discussed on four different levels: individuals, groups, organisations and networks. Furthermore contradictory developmental patterns are considered: global versus regional development, entrepreneurship on different scales, data availability versus data security, reality versus virtuality, education, and the ethics of multimedia and the Internet.     

OCRSpell: an interactive spelling correction system for OCR errors in text

In this paper, we describe a spelling correction system designed specifically for OCR-generated text that selects candidate words through the use of information gathered from multiple knowledge sources. This system for text correction is based on static and dynamic device mappings, approximate string matching, and n-gram analysis. Our statistically based, Bayesian system incorporates a learning feature that collects confusion information at the collection and document levels. An evaluation of the new system is presented as well. Received August 16, 2000 / Revised October 6, 2000     

Smart Clothing Prototype for the Arctic Environment

Continuous miniaturisation of electronic components has made it possible to create smaller and smaller electrical devices which can be worn and carried all the time. Together with developing fibre and textile technologies, this has enabled the creation of truly usable smart clothes that resemble clothes more than wearable computing equipment. These intelligent clothes are worn like ordinary clothing and provide help in various situations according to the application area. This paper describes the design and implementation of a survival smart clothing prototype for the arctic environment. Concept development, electrical design, and non-electrical features are discussed. The suit provides communication, positioning, and navigation aids for the user. Depending on the measurements of the human and the environment, the suit decides whether an emergency message should be sent. The user can control the system with a user interface called a Yo-Yo. The functionality of the suit has been tested in an arctic environment.     

Retrieval scheduling for collaborative multimedia presentations

The single-system approach is no longer sufficient to handle the load on popular Internet servers, especially for those offering extensive multimedia content. Such services have to be replicated to enhance their availability, performance, and reliability. In a highly replicated and available environment, server selection is an important issue. In this paper, we propose an application-layer broker (ALB) for this purpose. ALB employs a content-based, client-centric approach to negotiate with the servers and to identify the best server for the requested objects. ALB aims to maximize client buffer utilization in order to efficiently handle dynamic user interactions such as skip, reverse presentation, go back in time. We also present details of a collaborative multimedia presentation platform that we have developed based on ALB.     

Information Systems Curricula Evaluated by a Method Engineering Framework

Method engineering (ME) deals with the selection and assembly of situation-specific methods for information systems development. In this paper we use ME with a somewhat unusual perspective, that is, an educational one. We introduce a procedure for the evaluation of information systems curricula within an ME framework. Using this approach it is possible to quantitatively characterise and compare information systems curricula, showing their relative strengths and weaknesses. As an example we evaluate three model curricula (IS’90, IS’97 and ISCC’99) and analyse their differences and similarities.     

Designing Ubiquitous Computing Games – A Report from a Workshop Exploring Ubiquitous Computing Entertainment

We report from a Research Atelier that explored how ubiquitous computing could be applied to fun and entertainment. The Atelier lasted for five days, starting with two days of scenario development and brainstorming activities. This led to three fairly concrete – though very different – game ideas. The background and motivation for the Atelier is described, as well as the method used and the games developed. Correspondence to: Mr S. Bjork, PLAY Studio, Interactive Institute, Box 620, SE 40530 Goteborg, Sweden.     

The Use of a Formalised Risk Model in NHS Information System Development

Information systems (IS) and technology are used extensively throughout the National Health Service (NHS), and the 1998 national information strategy, ‘Information for Health’, sets out how the NHS will be developing and implementing IS to support patient care within the next decade. This new IS initiative is set against a mixed record of success of IS projects in the NHS, with a number of high-profile failures. This paper highlights the need to consider the ‘organisational issues’ involved in systems implementation to avoid failures. It goes on to advocate the use of a process-oriented and organisation studies-based model for risk analysis and management for use in NHS IS projects. Two famous NHS case studies are used to validate the model. It is concluded that there is a real need in the NHS for tools to better control the inherent risks involved in IS development and implementation. Ultimately, the success of IS projects in the NHS is crucial if they want to best utilise clinical and patient information, with the overall aim of improving the efficiency and standard of the nation’s health care.     

There’s More to Information Systems Development than Structured Approaches: Information Requirements Analysis as a Socially Mediated Process

Information systems (IS) development approaches are considered with particular reference to those aspects of the process most concerned with the determination of information requirements. The majority can be classified as adopting a unitary, objective perspective. This perspective fails to recognise the interpretative, inter-subjective nature of information and the importance of informal as well as formal data-processing systems. This paper aims to contribute to the discussion on socio-technical and soft approaches to IS development by providing a contrasting perspective on information requirements analysis as a process which is socially mediated. A framework is developed which places information requirements analysis in the context of strategic IS development. This locates social communication networks centrally in this process and raises implications for the practice of IS development, and of information requirements analysis.     

P2P信息检索及其优化策略

本文研究对等计算（P2P）环境中语义丰富的信息检索及其优化策略,提出了P2P信息检索系统（PIRS）,实现了P2P环境中语义丰富的信息检索,定义了一套评价PIRS效率的指标体系;明确了决定PIRS效率的关键因素并提出相应的解决策略,包括：基于向量空间模型的节点数据分类管理策略、基于节点聚类的系统数据管理策略以及自适应查询路由策略,并用实验结果验证了这些策略的有效性。     

Patterns of Mobile Interaction

The design of systems for mobile scenarios covers a wide range of issues, ranging from mobile networking to user interface design for mobile devices. Mobile applications often run distributed on several connected devices, used by many users simultaneously. Considering all issues related to mobile scenarios, a designer might be overwhelmed. As a solution, we propose a specific kind of design patterns which we call mobility patterns, derived from successful mobile applications. They allow a designer to re-use design elements as building blocks in their own designs. After describing the idea of mobility patterns, we give a brief overview of patterns we have identified so far. Two patterns are described in more detail with the help of our research platforms QuickStep and Pocket DreamTeam.     

Negotiating and Understanding Information Systems Requirements: The Use of Set Diagrams

A major contributor to the failure of information technology-based systems is the problem of understanding user or customer requirements in the initial analysis and requirements identification stage of development. This paper identifies and describes an approach to help overcome some of these problems, particularly the mismatch or understanding gap between the customer and the developer. The approach is intended to be used at the early stages of requirement determination and introduces techniques from operational research into the process. In particular set theory and Venn diagrams are used as a way of graphically representing the relationships and gaps in understanding that may exist. The benefit obtained from the use of the technique is partly in the graphical representations themselves but mainly in the dialogue and negotiation that result from the construction of the diagrams. The technique has been developed in a research study of retail organisations’ use of information technology in the UK and an example case study from the sector is used to illustrate and discuss the technique.     

Exploring the Suitability of Virtual Environments for Safety Training: Signals, Norms and Ambiguity in a Simulated Emergency Escape

This study aims at exploring the suitability of virtual environments for safety training in large public spaces. A virtual library was constructed which simulated many of the physical and normative characteristics of the ‘real’ university library which was the target of the virtual safety training project. In the virtual library, two different types of signals (fixed red signs vs. moving green arrows) for guiding people to the emergency exits were presented, and their efficacy on escape times was tested in three different conditions, differing with respect to the distance of participants from the escape exits (measured according to the number of corners separating participants from direct visual discovery of the emergency exit). No significant differences between the different kinds of signals were found, whereas surprising discrepancies among the three conditions appeared. The differences in performance in the three conditions were contingent upon the presence in the virtual library of peculiar environmental features embodying social norms – like a red ribbon indicating no transit. Uncertainty about the sense of such normative features in the context of the simulated emergency made some participants prone to peculiar knowledge-based errors consisting of inadequate sense-making of the normative aspects of the ongoing situation. This kind of error shows that the simulation succeeded in capturing one of the crucial characteristics of ‘real’ social context: ambiguity, which mostly depends on the fact that the social norms structuring public spaces and defining their legitimate uses are often ill defined and context dependent. Every valid experience in safety training requires coping with ambiguity in situations.     

A probabilistic justification for using tf×idf term weighting in information retrieval

This paper presents a new probabilistic model of information retrieval. The most important modeling assumption made is that documents and queries are defined by an ordered sequence of single terms. This assumption is not made in well-known existing models of information retrieval, but is essential in the field of statistical natural language processing. Advances already made in statistical natural language processing will be used in this paper to formulate a probabilistic justification for using tf×idf term weighting. The paper shows that the new probabilistic interpretation of tf×idf term weighting might lead to better understanding of statistical ranking mechanisms, for example by explaining how they relate to coordination level ranking. A pilot experiment on the TREC collection shows that the linguistically motivated weighting algorithm outperforms the popular BM25 weighting algorithm. Received: 17 December 1998 / Revised: 31 May 1999