On the efficiency of keyboard navigation in Web sites

An efficient keyboard access to Web sites is highly important for many groups of disabled users. However, the current design of most Web sites makes the efficient keyboard navigation nearly impossible. This paper investigates the performance of the keyboard and mouse navigation in Web pages. The comparison is based on the theoretical arguments and on two small studies. The results show that the current amount of keyboard support in common Web sites is far from being sufficient. Typical problems concerning keyboard support in Web sites are discussed, along with possible solutions and the related constraints.

Usage-based dynamic pricing of Web services for optimizing resource allocation

Web services technology is becoming an important technological trend in Web application development and integration. Based on open standards, such as SOAP, WSDL, and UDDI, Web services allow Web-based applications to communicate with each other through standardized XML messaging and to form loosely coupled distributed systems. Although the open feature of Web services benefits service providers in servicing consumers, the unlimited computing resources access of Web services to network bandwidth, storage throughput, and CPU time may lead to overexploitation of the resources when applications based on the Web services technology are widely accepted. Therefore, it is critical to optimize the operation of Web services, subject to the QoS requirements of service requests, to assure the total benefits of the service providers and the service consumers. This paper proposes a usage-based dynamic pricing approach to optimizing resource allocation of Web services in the principle of economics, and reports on a pilot implementation demonstrating the technical feasibility of the proposed approach.

Research on Internet use by Spanish-speaking users with blindness and partial sight

The results of an online questionnaire for Spanish-speaking Internet users with visual impairment are presented in this work. The research was carried out during 2002. The data collected shows that Internet is a very valuable tool for visually impaired people, as it allows them to access written information in an autonomous and instantaneous manner and to communicate with others through individual email and discussion lists. However, all users found frequent and important problems of accessibility in many web pages that prevent them from having complete access to the information and functionalities of those websites.

How people use presentation to search for a link: expanding the understanding of accessibility on the Web

It is well known that many Web pages are difficult to use for visually disabled people. Without access to a rich visual display, the intended structure and organisation of the page is obscured. To fully understand what is missing from the experience of visually disabled users, it is pertinent to ask how the presentation of Web pages on a standard display makes them easier for sighted people to use. This paper reports on an exploratory eye tracking study that addresses this issue by investigating how sighted readers use the presentation of the BBC News Web page to search for a link. The standard page presentation is compared with a “text-only” version, demonstrating both qualitatively and quantitatively that the removal of the intended presentation alters “reading” behaviours. The demonstration that the presentation of information assists task completion suggests that it should be re-introduced to non-visual presentations if the Web is to become more accessible. The conducted study also explored the extent to which algorithms that generate maps of what is perceptually salient on a page match the gaze data recorded in the eye tracking study. The correspondence between a page’s presentation, knowledge of what is visually salient, and how people use these features to complete a task might offer an opportunity to re-model a Web page to maximise access to its most important parts.

Device Management in the IMS

IMS is the only standardized way to offer IP based services that are enabled by one common core and all types of access networks and devices. The management of devices can benefit services enabling and improve user experience. This paper presents the device management issues in the IMS. Requirements of device management are presented and a management architecture is proposed to satisfy the requirements. The architecture utilizes distributed design by separating management and executing functionalities and provides service provisioning and tracing functionalities to application servers utilizing some IMS capabilities. Some approaches to integrate more IMS capabilities in device management architecture are discussed. A possible evaluation model for quality of device management from the perspective of user and management authority is proposed.

Tactile web browsing for blind people

Information on the World Wide Web becomes more and more important for our society. For blind people this is a chance to access more information for their everyday life. In this paper we propose novel methods to present web pages including graphical information on a tactile output device. We present a Mozilla Firefox Extension for the tactile rendering of web pages and for the handling of user interactions. This approach benefits from the Firefox built-in web page handling including parsing of HTML documents, formatting with cascading style sheets (CSS), handling of dynamic web content controlled by JavaScript code, etc. Graphical information can be explored and filtered interactively in a special mode for raster images and Scalable Vector Graphics (SVG). Mathematical expressions encoded in the mathematical markup language (MathML) are transformed directly into LaTeX or into a notation for blind people. The tactile web browser supports feedback that is provided via voice output.

An adaptive personalized news dissemination system

With the explosive growth of the Word Wide Web, information overload became a crucial concern. In a data-rich information-poor environment like the Web, the discrimination of useful or desirable information out of tons of mostly worthless data became a tedious task. The role of Machine Learning in tackling this problem is thoroughly discussed in the literature, but few systems are available for public use. In this work, we bridge theory to practice, by implementing a web-based news reader enhanced with a specifically designed machine learning framework for dynamic content personalization. This way, we get the chance to examine applicability and implementation issues and discuss the effectiveness of machine learning methods for the classification of real-world text streams. The main features of our system named PersoNews are: (a) the aggregation of many different news sources that offer an RSS version of their content, (b) incremental filtering, offering dynamic personalization of the content not only per user but also per each feed a user is subscribed to, and (c) the ability for every user to watch a more abstracted topic of interest by filtering through a taxonomy of topics. PersoNews is freely available for public use on the WWW ().

An exploratory study of the accessibility of state government Web sites

This paper focuses on Web accessibility. Relevant legislation and judicial decisions are reviewed, and prior empirical research is presented. This study presents the results from the Web accessibility analysis of the home pages of the 50 states and the District of Columbia. It found that twenty-nine percent of the home pages do not meet the requirements for Conformance Level A Web accessibility. Only one state meets Conformance Level AA standards, which are the minimum standards recommended for Web accessibility, and no state meets Conformance Level AAA standards. This paper also discusses how to address common accessibility problems.

Personalised e-learning through an educational virtual reality game using Web services

This paper describes how a personalised educational game architecture has been used in conjunction with Web services to provide remote access to the system. The educational game is a virtual reality adventure game that performs affective user modelling by measuring emotional characteristics of users. Virtual reality (VR) games are so popular among children and adolescents that can be used for the purposes of educational software to render it more attractive and motivating. The benefits of such an application can be maximised if it is available over the Web. Software applications that operate over the Web are targeted to a wide range of users. Hence they need a high degree of adaptivity and dynamic individualisation to each user that interacts with the application. This should include the students’ emotional state that affects their learning. However, the environment of a Web-based VR-game that performs user modelling is so demanding that the technology of Web services is necessary for its effective operation and interoperability. Moreover, reusability may be achieved for the user modelling component.

Goal-driven requirements analysis for hypermedia-intensive Web applications

Requirements analysis for Web applications still needs to employ effective RE practices to accommodate some distinctive aspects: capturing high-level communication goals, considering several user profiles, defining hypermedia-specific requirements, bridging the gap between requirements and Web design, and reusing requirements for an effective usability evaluation. Techniques should be usable, informal, require little training effort, and show relative advantage to project managers. On the basis of the i * framework, this paper presents a proposal for defining hypermedia requirements (concerning aspects such as content, interaction, navigation, and presentation) for Web applications. The model adopts a goal-driven approach coupled with scenario-based techniques, introduces a hypermedia requirement taxonomy to facilitate Web conceptual design, and paves the way for systematic usability evaluation. Particular attention is paid to the empirical validation of the model based on the perceived quality attributes theory. A case study developed with industrial partners is discussed.

Integrated access to legal literature through automated semantic classification

Access to legal information and, in particular, to legal literature is examined for the creation of a search and retrieval system for Italian legal literature. The design and implementation of services such as integrated access to a wide range of resources are described, with a particular focus on the importance of exploiting metadata assigned to disparate legal material. The integration of structured repositories and Web documents is the main purpose of the system: it is constructed on the basis of a federation system with service provider functions, aiming at creating a centralized index of legal resources. The index is based on a uniform metadata view created for structured data by means of the OAI approach and for Web documents by a machine learning approach, which, in this paper, has been assessed as regards document classification. Semantic searching is a major requirement for legal literature users and a solution based on the exploitation of Dublin Core metadata, as well as the use of legal ontologies and related terms prepared for accessing indexed articles have been implemented.

Information systems design: through adaptivity to ubiquity

In a globalised economy the accessibility of services becomes increasingly important for businesses. This has led to a demand that information systems should be ubiquitous in the sense that they are available to all users under all circumstances, everywhere and at all times, and independent of the access devices and channels used. The authors believe the key to meeting that demand is existence of an omnipresent media of interaction and existence of information systems that within that media adapt themselves to context parameters at run-time. The World Wide Web is considered as that omnipresent media. Thus, the task is left to design adaptive information systems in a way that avoids unnecessary replication. In this article it will be shown how context parameters can be utilised to enable system adaptivity. The latter is supposed to increase usability and targets the quality of use, the content, and the functionality. We propose using an algebraic approach that aids in providing the leanest appropriate interface via user typing and story boarding. Our approach furthermore limits the content delivered to a user to the amount that can be dealt with in a usage scenario. The latter is based on defining hyphenation points within the content.

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Universal access to information services—the need for user information and its relationship to device profiles

Users access information services with a variety of devices and with different interaction modes that depend on personal characteristics (including disabilities) and on the context of usage. With the appearance of mobile devices, the industry has focused its efforts on the standardization of device characteristics, thus giving to information providers some content adaptation facilities. However, little attention has been paid to the standardization of user profiles that will allow further customization and adaptation capabilities in mainstream services. This paper will present the authors experiences in outlining and implementing user profiles, as well as possible integration paths with device characteristics.

A user experience-based approach to home atmosphere control

The complex control problem of creating home atmospheres using light, music, and projected wall-art can be reduced by focusing on desired experience, rather than product functions and features. A case study is described in which subjective interpretations of living room atmospheres were measured and embedded into a prototype display system. A personalization mechanism is proposed to manage individual differences in atmosphere ratings, enabling a user model to evolve over time. To create a meaningful and simple control mechanism for a wide range of users, three interfaces were developed and studied, ranging from concrete to abstract control and from structured to exploratory navigation.

Reverse engineering relational databases to identify and specify basic Web services with respect to service oriented computing

Service-oriented computing (SOC) is the computing paradigm that utilizes services as a fundamental building block. Services are self-describing, open components intended to support composition of distributed applications. Currently, Web services provide a standard-based realization of SOC due to: (1) the machine-readable format (XML) of their functional and nonfunctional specifications, and (2) their messaging protocols built on top of the Internet. However, how to methodologically identify, specify, design, deploy and manage a sound and complete set of Web services to move to a service-oriented architecture (SOA) is still an issue. This paper describes a process for reverse engineering relational database applications architecture into SOA architecture, where SQL statements are insulated from the applications, factored, implemented, and registered as Web services to be discovered, selected, and reused in composing e-business solutions. The process is based on two types of design patterns: schema transformation pattern and CRUD operations pattern. First, the schema transformation pattern allows an identification of the services. Then the CRUD operations pattern allows a specification of the abstract part of the identified services, namely their port types. This process is implemented as a CASE tool, which assists analysts specifying services that implement common, reusable, basic business logic and data manipulation.

Resource holding times: computation and optimization

In scheduling hard-real-time systems, the primary objective is to meet all deadlines. We study the scheduling of such systems with the secondary objective of minimizing the duration of time for which the system locks each shared resource. We abstract out this objective into the resource hold time (rht)—the largest length of time that may elapse between the instant that a system locks a resource and the instant that it subsequently releases the resource, and study properties of the rht. We present an algorithm for computing resource hold times for every resource in a task system that is scheduled using Earliest Deadline First scheduling, with resource access arbitrated using the Stack Resource Policy. We also present and prove the correctness of algorithms for decreasing these rht’s without changing the semantics of the application or compromising application feasibility.

Digital switchover or digital divide: a prognosis for usable and accessible interactive digital television in the UK

The move toward digital switchover increases content and introduces interactive services available through the television. UK legislation advocates universal access and equitable provision of services, across all platforms and equipment, particularly for ‘vulnerable’ groups. However, key aspects of usability and accessibility have been overlooked by those responsible for encouraging this new infrastructure’s inclusive development. Aspects of previous interactive television provision and developments in web accessibility appear to have been ignored, along with findings from relevant user-centred research and even from specifically commissioned reports. This paper will identify these issues and discuss their impact on the inclusiveness of DTV.