Web applications often need to present the user new information in the context of their current activity. Designers rely on a range of UI elements and visual techniques to present the new content to users, such as pop-ups, message icons, and marquees. Web designers need to select which technique to use depending on the centrality of the information and how quickly they need a reaction. However, designers often rely on intuition and anecdotes rather than empirical evidence to drive their decision-making as to which presentation technique to use. This work represents an attempt to quantify these presentation style decisions. We present a large (n=1505) user study that compares 15 visual attention-grabbing techniques with respect to reaction time, noticeability, annoyance, likability, and recall. We suggest glowing shadows and message icons with badges, as well as more possibilities for future work.

Current location-based services (LBS) typically allow users to locate points of interest (POI) in their vicinity but can detract from the user's emotional experience of exploring a new location. In this paper, we examine how cues in the form of popular music (musicons) can emotionally engage users and enhance their experience of discovering nearby POIs serendipitously in unfamiliar places. The primary contribution of this paper is a field study, in which we evaluate the performance and emotional engagement of different types of audio-based cues for directing users' attention to specific POIs. Musicons and mixed-modality cues performed close to visual and speech cues, and significantly better than auditory icons, for POI identification while creating a much more pleasant and engaging user experience. We conclude that cues for POI discovery need not always be as explicit as the baseline visual cues. Indeed, the most challenging cues, auditory icons, led to a heightened sense of autonomy.

We have designed and implemented Friendlee, a mobile social networking application for close relationships. Friendlee analyzes the user's call and messaging activity to form an intimate network of the user's closest social contacts while providing ambient awareness of the user' social network in a compelling, yet non-intrusive manner.

Automatic Web service composition (WSC) is a key component of flexible SOAs. We address WSC at the profile/capability level, where preconditions and effects of services are described in an ontology. In its most expressive formulation, WSC has two sources of complexity: (A) a combinatorial explosion of the services composition space, and (B) worst-case exponential reasoning is needed to determine whether the underlying ontology implies that a particular composition is a solution. Any WSC technology must hence choose a trade-off between scalability and expressivity. We devise new methods for finding better trade-offs. We address (A) by techniques for the automatic generation of heuristic functions. We address (B) by approximate reasoning techniques for the fully expressive case, and by identifying a sub-class where the required reasoning is tractable. We show empirically that our approach scales gracefully to large pools of pre-discovered services, in several test cases.

A common perception is that there are two competing visions for the future evolution of the Web: the Semantic Web and Web 2.0. A closer look, though, reveals that the core technologies and concerns of these two approaches are complementary and that each field can and must draw from the other's strengths. We believe that future web applications will retain the Web 2.0 focus on community and usability, while drawing on Semantic Web infrastructure to facilitate mashup-like information sharing. However, there are several open issues that must be addressed before such applications can become commonplace. In this paper, we outline a semantic weblogs scenario that illustrates the potential for combining Web 2.0 and Semantic Web technologies, while highlighting the unresolved issues that impede its realization. Nevertheless, we believe that the scenario can be realized in the short-term. We point to recent progress made in resolving each of the issues as well as future research directions for each of the communities.

A key challenge for dynamic Web service selection is that Web services are typically highly configurable and service requesters often have dynamic preferences on service configurations. Current approaches, such as WS-Agreement, describe Web services by enumerating the various possible service configurations, an inefficient approach when dealing with numerous service attributes with large value spaces. We model Web service configurations and associated prices and preferences more compactly using utility function policies, which also allows us to draw from multi-attribute decision theory methods to develop an algorithm for optimal service selection. In this paper, we present an OWL ontology for the specification of configurable Web service offers and requests, and a flexible and extensible framework for optimal service selection that combines declarative logic-based matching rules with optimization methods, such as linear programming. Assuming additive price/preference functions, experimental results indicate that our algorithm introduces an overhead of only around 2 sec. compared to random service selection, while giving optimal results. The overhead, as percentage of total time, decreases as the number of offers and configurations increase.

Increased availability of mobile computing, such as personal digital assistants (PDAs), creates the potential for constant and intelligent access to up-to-date, integrated and detailed information from the Web, regardless of one's actual geographical position.Intelligent question-answering requires the representation of knowledge from various domains, such as the navigational and discourse context of the user, potential user questions, the information provided by Web services and so on, for example in the form of ontologies.Within the context of the SmartWeb project, we have developed a number of domain-specific ontologies that are relevant for mobile and intelligent user interfaces to open-domain question-answering and information services on the Web.To integrate the various domain-specific ontologies, we have developed a foundational ontology, the SmartSUMO ontology, on the basis of the DOLCE and SUMO ontologies.This allows us to combine all the developed ontologies into a single SmartWeb Integrated Ontology 1 (SWIntO) having a common modeling basis with conceptual clarity and the provision of ontology design patterns for modeling consistency.In this paper, we present SWIntO, describe the design choices we made in its construction, illustrate the use of the ontology through a number of applications, and discuss some of the lessons learned from our experiences.1 http://www.smartweb-project.org 2 SmartWeb is a large international

In recent years, electronic markets have gained much attention as institutions to allocate goods and services efficiently between buyers and sellers. However, calculating suitable allocations between buyers and sellers in such markets can easily become very tricky, particularly if the services and goods involved are complex and described by multiple attributes. Since such trading objects typically provide various configurations with different corresponding prices, complex pricing functions and purchase preferences have to be taken into account when computing allocations. In this paper, we present a policy description framework that draws from utility theory to capture configurable products with multiple attributes. The framework thus allows the declarative description of seller pricing policies as well as buyer preferences over these configurations. As part of the framework, we present a machine-processible representation language for the policies and a method to evaluate different trading object configurations based on these policies. In addition, we show how policies can be aggregated and how the framework can be applied in a Web service selection scenario.

No abstract available.

The Web plays a critical role in hosting Web communities, their content and interactions. A prime example is the open source software (OSS) community, whose members, including software developers and users, interact almost exclusively over the Web, constantly generating, sharing and refining content in the form of software code through active interaction over the Web on code design and bug resolution processes. The Semantic Web is an envisaged extension of the current Web, in which content is given a well defined meaning, through the specification of metadata and ontologies, increasing the utility of the content and enabling information from heterogeneous sources to be integrated. We developed a prototype Semantic Web system for OSS communities, Dhruv. Dhruv provides an enhanced semantic interface to bug resolution messages and recommends related software objects and artifacts. Dhruv uses an integrated model of the OpenACS community, the software, and the Web interactions, which is semi-automatically populated from the existing artifacts of the community.