Intelligibility and user control of context-aware application behaviours

Context-aware applications adapt their behaviours according to changes in user context and user requirements. Research and experience have shown that such applications will not always behave the way as users expect. This may lead to loss of users' trust and acceptance of these systems. Hence, context-aware applications should (1) be intelligible (e.g., able to explain to users why it decided to behave in a certain way), and (2) allow users to exploit the revealed information and apply appropriate feedback to control the application behaviours according to their individual preferences to achieve a more desirable outcome. Without appropriate mechanisms for explanations and control of application adaptations, the usability of the applications is limited. This paper describes our on going research and development of a conceptual framework that supports intelligibility of model based context-aware applications and user control of their adaptive behaviours. The goal is to improve usability of context-aware applications

Fine-tuning a context-aware system application by using user-centred design methods

Context-Aware Systems in the home environment can provide an effective solution for supporting wellbeing and autonomy for the elderly. The definition and implementation of the system architecture for a particular assisted living healthcare application entail both technological and usability challenges. If issues regarding users’ concerns and desires are taken into account in the early stages of the system development users can benefit substantially more from this technology. In this paper, we describe our initial experiences with different user-centred design methods, as they are applied in the process of fine-tuning a context-aware system architecture to improve quality of life for elderly THR patients (Total Hip Replacement). The insights resulting from this approach result in a clearer functional specification towards a better fit with the user needs regarding information need of the patient as well as the physiotherapist. Important system requirements as timing and content of the feedback are much more fruitful in an earlier phase of the development process. User-centred design methods help to better understand the needed functional features of a context-aware system, thereby saving time and helping developers to improve adoption of the system by the users

Investigating context-aware clues to assist navigation for visually impaired people

It is estimated that 7.4 million people in Europe are visually impaired [1]. Limitations of traditional mobility aids (i.e. white canes and guide dogs) coupled with a proliferation of context-aware technologies (e.g. Electronic Travel Aids, Global Positioning Systems and Geographical Information Systems), have stimulated research and development into navigational systems for the visually impaired. However, current research appears very technology focused, which has led to an insufficient appreciation of Human Computer Interaction, in particular task/requirements analysis and notions of contextual interactions. The study reported here involved a smallscale investigation into how visually impaired people interact with their environmental context during micro-navigation (through immediate environment) and/or macro-navigation (through distant environment) on foot. The purpose was to demonstrate the heterogeneous nature of visually impaired people in interaction with their environmental context. Results from a previous study involving sighted participants were used for comparison. Results revealed that when describing a route, visually impaired people vary in their use of different types of navigation clues - both as a group, when compared with sighted participants, and as individuals. Usability implications and areas for further work are identified and discussed

Is my configuration any good: checking usability in an interactive sensor-based activity monitor

We investigate formal analysis of two aspects of usability in a deployed interactive, configurable and context-aware system: an event-driven, sensor-based homecare activity monitor system. The system was not designed from formal requirements or specification: we model the system as it is in the context of an agile development process. Our aim was to determine if formal modelling and analysis can contribute to improving usability, and if so, which style of modelling is most suitable. The purpose of the analysis is to inform configurers about how to interact with the system, so the system is more usable for participants, and to guide future developments. We consider redundancies in configuration rules defined by carers and participants and the interaction modality of the output messages.Two approaches to modelling are considered: a deep embedding in which devices, sensors and rules are represented explicitly by data structures in the modelling language and non-determinism is employed to model all possible device and sensor states, and a shallow embedding in which the rules and device and sensor states are represented directly in propositional logic. The former requires a conventional machine and a model-checker for analysis, whereas the latter is implemented using a SAT solver directly on the activity monitor hardware. We draw conclusions about the role of formal models and reasoning in deployed systems and the need for clear semantics and ontologies for interaction modalities

Usability Testing Methodology of Proactive HMIs for Virtual Control Room

The aim of this thesis is to develop methodology for usability testing of proactive HMIs. Usability is an important aspect of functionality of any Human-Machine Interface (HMI) since users directly interact with interfaces. Usability testing is, therefore, an important part of the development of HMIs. Emerging technologies, such as mobile devices and context-aware systems, pose new challenges for HMI developers due to new features and functionality. Since context of use is essential for HMI usability, HMI usability testing becomes especially important in context-aware systems. Both, the user and the HMI, need to have the same interpretation of context of use to ensure the usability of the HMI. At the same time, the context interpretation of a system should not conflict with the common sense of a user. A proactive HMI can be run on top of a context-aware system and it tries to predict next feasible action based on the context. There are two challenges for testing usability in this kind of HMI. Firstly, the proactive HMI is a new technology and there are no previous studies made on proactive HMI usability testing. It has been conjectured that new features like proactivity, adaptivity and multimodality may challenge the results of measurements for earlier deffined attributes of usability (SFS-EN ISO 1998) and return the misleading results. Therefore, the usability testing methodology should be further elaborated in order to capture the usability of the proactive features. Secondly, the HMI is ment to run on mobile devices. Mobile devices have many constrains, such as limited computational resources, connectivity issues and varying display resolutions. Despite of these constrains, information should be accessible at any place and any time with mobile devices. This thesis proposes a usability testing methodology of proactive HMI developed for Virtual Control Room (VCR). VCR is a proactive content-managing context-aware system; which was developed to increase the usability of embedded systems and human decision-making in data intensive environment. The methodology proposed in this thesis is based on Human-Centered Design (HCD) principles and consists of two stages: alpha (α) and beta (β) stage. In the α stage, traditional usability testing techniques are used with the addition of questions focused on getting information about what kind of proactive functionality the users would like to have on the HMI. In the β stage, a comparison of two different versions of the HMI, static and proactive, is conducted. This was done in order to test that the proactive functionality works well. It was found that the standard attributes of usability are not enough to capture the usability of the proactive HMIs: thus the rates for efficiency (which is measured as a function of time) were low despite of positive verbal feedbacks from the participants. Assuming the importance of context of use, a new usability attribute – transparency – was created to capture usability parameters related to proactivity. The transparency was measured via the participants’ reports on how easier they understand the HMIs elements and are capable to link them with a goal. In order to illustrate the methodology in use, two use cases were selected to develop the usability testing methodology. In the first one, an HMI was being developed for Building Management (BM) domain. The HMI was developed for an automated five building complex to assist the living conditions in the buildings. In total this encompassed 25 apartments that were controlled via the VCR system. Another use case was an HMI that was being developed for Production Management (PM) domain. The HMI was generic software to monitor and control production line systems. The approach selected in this thesis, allows an efficient way to receive feedback from usability tests and use this feedback to improve the proactive HMI. It is expected that the methodology developed in this thesis can be used to test other proactive HMI developed for automation systems

Towards Trust-Aware Human-Automation Interaction: An Overview of the Potential of Computational Trust Models

Several computational models have been proposed to quantify trust and its relationship to other system variables. However, these models are still under-utilised in human-machine interaction settings due to the gap between modellers’ intent to capture a phenomenon and the requirements for employing the models in a practical context. Our work amalgamates insights from the system modelling, trust, and human-autonomy teaming literature to address this gap. We explore the potential of computational trust models in the development of trust-aware systems by investigating three research questions: 1- At which stages of development can trust models be used by designers? 2- how can trust models contribute to trust-aware systems? 3- which factors should be incorporated within trust models to enhance models’ effectiveness and usability? We conclude with future research directions

Rover-II: A Context-Aware Middleware for Pervasive Computing Environment

It is well recognized that context plays a significant role in all human endeavors. All decisions are based on information which has to be interpreted in context. By making information systems context-aware we can have systems that significantly enhance human capabilities to make critical decisions. A major challenge of context-aware systems is to balance usability with generality and extensibility. The relevant context changes depending on the particular application. The model used to represent the context and its relationship to entities must be general enough to allow additions of context categories without redesign while remaining usable across many applications. Also, while efforts are put in by application designers and developers to make applications context-aware, these efforts are customized to specific needs of the target application, and only certain common contexts like location and time are taken into account. Therefore, a general framework is called for that can (i) efficiently maintain, represent and integrate contextual information, (ii) act as an integration platform where different applications can share contexts and (iii) provide relevant services to make efficient use of the contextual information. This dissertation presents: * a generic and effective context model - Rover Context Model (RoCoM) that is structured around four primitives: entities, events, relationships, and activities; and practically usable through the concept of templates, * a flexible, extensible and generic ontology - Rover Context Model Ontology (RoCoMO) supporting the model, that addresses the shortcomings of existing ontologies, * an effective mechanism of modeling the context of a situation, through the concept of relevant context, with the help of situation graph, efficiently handling and making best use of context information, * a context middleware - Rover-II, which serves as a framework for contextual information integration, that could be used not just to store and compile the contextual information, but also integrate relevant services to enhance the context information; and more importantly, enable sharing of context among the applications subscribed to it, * the initial design and implementation of a distributed architecture for Rover-II, following a P2P arrangement inspired from Tapestry, The above concepts are illustrated through M-Urgency, a context-aware public safety system that has been deployed at the University of Maryland Police Department

Towards a user-centric and multidisciplinary framework for designing context-aware applications

Research into context-aware computing has not sufficiently addressed human and social aspects of design. Existing design frameworks are predominantly software orientated, make little use of cross-disciplinary work, and do not provide an easily transferable structure for cross-application of design principles. To address these problems, this paper proposes a multidisciplinary and user-centred design framework, and two models of context, which derive from conceptualisations within Psychology, Linguistics, and Computer Science. In a study, our framework was found to significantly improve the performance of postgraduate students at identifying the context of the user and application, and the usability issues that arise

A context‐aware approach to defend against unauthorized reading and relay attacks in RFID systems

Radio frequency identification (RFID) systems are becoming increasingly ubiquitous in both public and private domains. However, because of the inherent weaknesses of underlying wireless radio communications, RFID systems are plagued with a wide variety of security and privacy threats. A large number of these threats arise because of the tag's promiscuous response to any reader requests. This renders sensitive tag information easily subject to unauthorized reading . Promiscuous tag response also incites different forms of relay attacks whereby a malicious colluding pair, relaying messages between a tag and a reader, can successfully impersonate the tag without actually possessing it. Because of the increasing ubiquity of RFID devices, there is a pressing need for the development of security primitives and protocols to defeat unauthorized reading and relay attacks. However, currently deployed or proposed solutions often fail to satisfy the constraints and requirements of the underlying RFID applications in terms of (one or more of) efficiency, security, and usability. This paper proposes a novel research direction, one that utilizes sensing technologies, to tackle the problems of unauthorized reading and relay attacks with a goal of reconciling the requirements of efficiency, security, and usability. The premise of the proposed work is based on a current technological advancement that enables many RFID tags with low‐cost sensing capabilities. The on‐board tag sensors will be used to acquire useful contextual information about the tag's environment (or its owner, or the tag itself). For defense against unauthorized reading and relay attacks, such context information can be leveraged in two ways. First, contextual information can be used to design context‐aware selective unlocking mechanisms so that tags can selectively respond to reader interrogations and thus minimize the likelihood of unauthorized reading and “ghost‐and‐leech” relay attacks. Second, contextual information can be used as a basis for context‐aware secure transaction verification to defend against special types of relay attacks involving malicious readers. Copyright © 2011 John Wiley & Sons, Ltd. This paper proposes a novel research direction, one that utilizes sensing technologies to tackle the challenging problems of unauthorized reading and relay attacks in radio frequency identification systems. First, contextual information is used to design context‐aware selective unlocking mechanisms, so that tags can selectively respond to reader interrogations and, thus, minimize the likelihood of unauthorized reading and “ghost‐and‐leech” relay attacks. Second, contextual information is used as a basis for context‐aware secure transaction verification to defend against special types of relay attacks involving malicious readers.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109577/1/sec404.pd

Mobile recommender apps with privacy management for accessible and usable technologies

The paper presents the preliminary results of an ongoing survey of the use of computers and mobile devices, interest in recommender apps and knowledge and concerns about privacy issues amongst English and Italian speaking disabled people. Participants were found to be regular users of computers and mobile devices for a range of applications. They were interested in recommender apps for household items, computer software and apps that met their accessibility and other requirements. They showed greater concerns about controlling access to personal data of different types than this data being retained by the computer or mobile device. They were also willing to make tradeoffs to improve device performance