Exploiting User Interests to Characterize Navigational Patterns in Web Browsing Assistance

In order to be capable of exploiting context for pro-active information recommendation, agents need to extract and understand user activities based on their knowledge of the user interests. In this paper, we propose a novel approach for context-aware recommendation in browsing assistants based on the integration of user profiles, navigational patterns and contextual elements. In this approach, user profiles built using an unsupervised Web page clustering algorithm are used to characterize user ongoing activities and behavior patterns. Experimental evidence show that using longer-term interests to explain active browsing goals user assistance is effectively enhanced.

Reality mining: sensing complex social systems

We introduce a system for sensing complex social systems with data collected from 100 mobile phones over the course of 9 months. We demonstrate the ability to use standard Bluetooth-enabled mobile telephones to measure information access and use in different contexts, recognize social patterns in daily user activity, infer relationships, identify socially significant locations, and model organizational rhythms.

Acoustic environment as an indicator of social and physical context

Acoustic environments provide many valuable cues for context-aware computing applications. From the acoustic environment we can infer the types of activity, communication modes and other actors involved in the activity. Environmental or background noise can be classified with a high degree of accuracy using recordings from microphones commonly found in PDAs and other consumer devices. We describe an acoustic environment recognition system incorporating an adaptive learning mechanism and its use in a noise tracker. We show how this information is exploited in a mobile context framework. To illustrate our approach we describe a context-aware multimodal weather forecasting service, which accepts spoken or written queries and presents forecast information in several forms, including email, voice and sign languages.

Bridging the physical and virtual worlds by local connectivity-based physical selection

The prevalent visions of ambient intelligence emphasise natural interaction between user and functions and services embedded in the environment or available through mobile devices. In these scenarios the physical and virtual worlds seamlessly gear into each other, making crossing the border between these worlds natural or even invisible to the user. The bottleneck in reaching these scenarios appear in the natural mapping between the physical objects and their virtual counterparts. The emergence of local connectivity in mobile devices opens possibilities for implementing novel user interface paradigms to enhance this mapping. We present physical selection paradigm for implementing an intuitive human technology interaction for mobile devices. In order to demonstrate the feasibility of the paradigm we implemented two experimental set-ups using commercially available smart phones with IrDA connectivity. The experiments involved selecting a website by physically pointing at its symbol and making a phone call by pointing at an icon representing the person to be called. In tentative user experiments the physical selection method was more time-efficient and it was perceived more positively by the users than a conventional method.

Enabling Routes of Road Network Constrained Movements as Mobile Service Context

With the continuing advances in wireless communications, geo-positioning, and portable electronics, an infrastructure is emerging that enables the delivery of on-line, location-enabled services to very large numbers of mobile users. A typical usage situation for mobile services is one characterized by a small screen and no keyboard, and by the service being only a secondary focus of the user. Under such circumstances, it is particularly important to deliver the “right” information and service at the right time, with as little user interaction as possible. This may be achieved by making services context aware. Mobile users frequently follow the same route to a destination as they did during previous trips to the destination, and the route and destination constitute important aspects of the context for a range of services. This paper presents key concepts underlying a software component that identifies and accumulates the routes of a user along with their usage patterns and that makes the routes available to services. The problems associated with of route recording are analyzed, and algorithms that solve the problems are presented. Experiences from using the component on logs of GPS positions acquired from vehicles traveling within a real road network are reported.

Modeling contextual security policies

As computer infrastructures become more complex, security models must provide means to handle more flexible and dynamic requirements. In the Organization Based Access Control (OrBAC) model, it is possible to express such requirements using the notion of context. In OrBAC, each security rule (permission, prohibition, obligation or dispensation) only applies in a given context. A context is viewed as an extra condition that must be satisfied to activate a given security rule. In this paper, we present a taxonomy of different types of context and investigate the data the information system must manage in order to deal with these different contexts. We then explain how to model and evaluate them in the OrBAC model.

Understanding and capturing people’s privacy policies in a mobile social networking application

A number of mobile applications have emerged that allow users to locate one another. However, people have expressed concerns about the privacy implications associated with this class of software, suggesting that broad adoption may only happen to the extent that these concerns are adequately addressed. In this article, we report on our work on PeopleFinder, an application that enables cell phone and laptop users to selectively share their locations with others (e.g. friends, family, and colleagues). The objective of our work has been to better understand people’s attitudes and behaviors towards privacy as they interact with such an application, and to explore technologies that empower users to more effectively and efficiently specify their privacy preferences (or “policies”). These technologies include user interfaces for specifying rules and auditing disclosures, as well as machine learning techniques to refine user policies based on their feedback. We present evaluations of these technologies in the context of one laboratory study and three field studies.

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Understanding the behavior of mobile data services consumers

Due to rapid advances in the Internet and wireless technologies, a ubiquitous computing world is becoming a reality in the form of mobile computing. At the center of this phenomenon is mobile data services which arise from the convergence of advanced mobile communication technologies with data services. Despite the rapid growth in mobile data services, research into consumers’ usage behavior is scarce. This study attempts to identify and empirically assess the factors that drive consumers’ acceptance of mobile data services. A research model based on the decomposed theory of planned behavior and incorporating factors that represent personal needs and motivations in using mobile data services is presented. The model is tested via an online survey of 811 consumers of four categories of mobile data services (i.e., communications, information content, entertainment, and commercial transactions) associated with different usage contexts. We found that attitude, social influence, media influence, perceived mobility, and perceived monetary value influence consumers’ intention to continue usage of mobile data services. In addition, perceived ease of use, perceived usefulness, and perceived enjoyment influence attitude toward continued usage of mobile data services. Finally, separate analysis of the different categories of mobile data services highlights the influence of individual usage context on consumers’ behavior.

COMUNICAR: designing a multimedia, context-aware human-machine interface for cars

The European Union co-funded COMUNICAR (communication multimedia unit inside car) project designed and developed an integrated multimedia human–machine interface (HMI) able to manage a wide variety of driver information systems (from entertainment to safety). COMUNICAR proposed an innovative information provision paradigm, in which the on-vehicle HMI is able to tailor the delivery of the information in real time according to the actual driving context and the drivers workload. COMUNICAR adopted a user-centred design process involving an iterative development based on extensive user tests since the early phases of the project. This approach was particularly useful to define and improve the layout of the user interface and specify the rules that decide the scheduling and the modalities of the delivery of the information messages to the driver. This paper introduces the COMUNICAR concept and the user-centred flow of design. Then, a concrete case of user-test driven, iterative improvement of a systems functionality is presented. We also briefly describe two software tools that we have designed to enhance the development process in a user-centred perspective. Finally, the future evolution of the concept of smart and safe information scheduling is sketched and discussed.

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Understanding mobile contexts

Mobile urban environments present a challenge for context-aware computers because they differ from fixed indoor contexts such as offices, meeting rooms, and lecture halls in many important ways. Internal factors such as tasks and goals are different—external factors such as social resources are dynamic and unpredictable. An empirical, user-centred approach is needed to understand mobile contexts. In this paper, we present insights from an ethnomethodologically inspired study of 25 adult urbanites in Helsinki. The results describe typical phenomena in mobility: how situational and planned acts intermesh in navigation, how people construct personal and group spaces, and how temporal tensions develop and dissolve. Furthermore, we provide examples of social solutions to navigation problems, examine mobile multitasking, and consider design implications for mobile and context-aware human–computer interaction.

Intelligent Network Provisioning for Dynamically Downloadable Applications in Beyond 3G Mobile Networks

Mobile communications beyond 3G will integrate different (but complementary) access technologies into a common platform to deliver value-added services and multimedia content in an optimum way. However, the numerous possible configurations of mobile networks complicated the dynamic deployment of mobile applications. Therefore, research is intensely seeking a service provisioning framework that is technology-independent, supports multiple wireless network technologies, and can interwork high-level service management tasks to network management operations. This paper presents an open value chain paradigm, a model for downloadable applications and a mediating platform for service provisioning in beyond 3G mobile settings. Furthermore, we introduce mechanisms that support a coupled interaction between service deployment and network configuration operations, focusing on the dynamic provisioning of QoS state to data path devices according to the requirements of dynamically downloadable mobile value-added services (VAS).

A grouped P2P network for scalable grid information services

Information services play a crucial role in grid environments in that the state information can be used to facilitate the discovery of resources and the services available to meet user requirements, and also to help tune the performance of a grid system. However, the large size and dynamic nature of the grid brings forth a number of challenges for information services. This paper presents PIndex, a grouped peer-to-peer network that can be used for scalable grid information services. PIndex builds on Globus MDS4, but introduces peer groups to dynamically split the large grid information search space into many small sections to enhance its scalability and resilience. PIndex is subsequently modeled with Colored Petri Nets for performance evaluation. The simulation results show that PIndex is scalable and resilient in dealing with a large number of peer nodes.

Using trust assumptions with security requirements

Assumptions are frequently made during requirements analysis of a system about the trustworthiness of its various components (including human components). These trust assumptions, whether implicit or explicit, affect the scope of the analysis, derivation of security requirements, and in some cases how functionality is realized. This paper presents trust assumptions in the context of analysis of security requirements. A running example shows how trust assumptions can be used by a requirements engineer to help define and limit the scope of analysis and to document the decisions made during the process. The paper concludes with a case study examining the impact of trust assumptions on software that uses the secure electronic transaction specification.

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Modeling decisions under uncertainty in adaptive user interfaces

The present work proposes a methodological approach for modeling adaptation decisions and for solving the problem of integrating existing as well as acquired knowledge in the decision module of an adaptive interface. So far, most applications do not exploit in full the value of data originating from user models or knowledge acquisition engines that monitor the user and the context. The proposed decision theoretic model is represented through specifically structured influence diagrams. It provides to designers and developers a specific method to encode user and context information, as well as other crucial decision factors, to be subsequently used in the decision making process regarding user interface adaptation actions. Such a process is driven by the definition of relevant utilities referring to the design of a user interface. The proposed model guides designers and developers of an adaptive or intelligent interface to integrate, without conflicts and incoherence, design strategies, design goals, user goals, alternative constituents, user profile, context and application domain knowledge. An illustrative example of the analyzed modeling method is presented.

A calendar based Internet content pre-caching agent for small computing devices

We described in earlier publications the principles of a system where Internet content would be pre-cached, based on contextual information obtained from a user’s electronic calendar. The model for such a system envisioned a set of cooperating agents, distributed on a user’s desktop and mobile device, which would be responsible for making decisions on the context and preferences of the user, and downloading the relevant internet content through a land-based broadband connection and storing it on the mobile device. This paper presents and discusses established pre-caching techniques and their suitability for use on mobile information access scenarios. It proceeds in describing the implementation details of an alternative approach, a calendar-based pre-caching system and presents the findings of tests that were made with human subjects on such a system.

Attitudes to telecare among older people,professional care workers and informal carers: a preventative strategy or crisis management?

This paper reports findings from an attitudinal survey towards telecare that emerged from 22 focus groups comprising 92 older people, 55 professional stakeholders and 39 carers. These were convened in three different regions of England as a precursor to telecare service development. The results from this study suggest that informants’ views were shaped by prior knowledge of conventional health and social care delivery in their locality, and the implication is that expectations and requirements with respect to telecare services in general are likely to be informed by wider perceptions about the extent to which community care should operate as a preventative strategy or as a mechanism for crisis management.

User experience of communication before and during rendezvous: interim results

This paper reports on a diary study of rendezvousing as performed by university students. The study compares students experience of communication before and during rendezvous. During rendezvous, students rated several aspects of the experience of communication lower than before rendezvous. This impairment of experience is attributed to the cumulative effects of the following aspects of the context of use: noise, multiple task performance, conflict with social norms, incomplete network coverage, time pressure and conflict with preferred life paths. User performance goals for context-aware communication systems are discussed.

Acquiring and incorporating state-dependent timing requirements

Some real-time systems are designed to deliver services to objects that are controlled by external sources. Their services must be delivered on a timely basis, and the system fails when some services are delivered too late. In general, the timing requirements of the system may change when the states of the objects monitored by the system change. Such a system may fail if the timing requirements which it is designed to meet are erroneous. It may underutilize resources and consequently be costly or unreliable if the requirements are too stringent. Hence, one must identify how changes in object states call for changes in system requirements and how these changes should be incorporated into the design and implementation of the system. This paper first describes a methodology to determine timing requirements and to take into account requirement changes at runtime. The method is based on several timing requirement determination schemes. Simulation data show that these schemes are effective for applications such as mobile IP hand-offs. The paper then discusses how to incorporate this methodology in the system architecture and in the development process.

How relative absolute can be: SUMI and the impact of the nature of the task in measuring perceived software usability

This paper addresses the possibility of measuring perceived usability in an absolute way. It studies the impact of the nature of the tasks performed in perceived software usability evaluation, using for this purpose the subjective evaluation of an application’s performance via the Software Usability Measurement Inventory (SUMI). The paper reports on the post-hoc analysis of data from a productivity study for testing the effect of changes in the graphical user interface (GUI) of a market leading drafting application. Even though one would expect similar evaluations of an application’s usability for same releases, the analysis reveals that the output of this subjective appreciation is context sensitive and therefore mediated by the research design. Our study unmasked a significant interaction between the nature of the tasks used for the usability evaluation and how users evaluate the performance of this application. This interaction challenges the concept of absolute benchmarking in subjective usability evaluation, as some software evaluation methods aspire to provide, since subjective measurement of software quality will be affected most likely by the nature of the testing materials used for the evaluation.

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Planners, navigators, and pragmatists: collaborative wayfinding using a single mobile phone

Shared use of mobile devices is increasingly prevalent in both research prototypes and in practice, however, little is known as to how to support best this interaction paradigm. In this paper, we present a study examining how pairs share a single mobile phone during a collaborative wayfinding activity. We provide a classification of strategies, role relationships and phone interactions employed to conduct the wayfinding activities in our study. While acknowledging that the factors determining how the phone was shared are nuanced and intertwined, our results illustrate how differences in the mobile application’s interface influenced shared use, wayfinding strategy and outcome.