Processing Structured Hypermedia : A Matter of Style

With the introduction of the World Wide Web in the early nineties, hypermedia has become the uniform interface to the wide variety of information sources available over the Internet. The full potential of the Web, however, can only be realized by building on the strengths of its underlying research fields. This book describes the areas of hypertext, multimedia, electronic publishing and the World Wide Web and points out fundamental similarities and differences in approaches towards the processing of information. It gives an overview of the dominant models and tools developed in these fields and describes the key interrelationships and mutual incompatibilities. In addition to a formal specification of a selection of these models, the book discusses the impact of the models described on the software architectures that have been developed for processing hypermedia documents. Two example hypermedia architectures are described in more detail: the DejaVu object-oriented hypermedia framework, developed at the VU, and CWI's Berlage environment for time-based hypermedia document transformations

Web browser accessibility using open source software

A Web browser provides a uniform user interface to different types of information. Making this interface universally accessible and more interactive is a long term goal still far from being achieved. Universally accessible browsers require novel interaction modalities and additional functionalities, for which existing browsers tend to provide only partial solutions. Although functionality for Web accessibility can be found as open source and free software components, their reuse and integration is complex because they were developed in diverse implementation environments, following standards and conventions incompatible with the Web. To enable the integration of existing partial solutions within a mainstream Web browser environment, we have developed a middleware infrastructure, AMICO:WEB. This enables browser access to a wide variety of open source and free software components. The main contribution of AMICO:WEB is in enabling the syntactic interoperability between Web extension mechanisms and a variety of integration mechanisms used by open source and free software components. It als

Integrating heterogeneous open-source software into web browsers using AMICO:WEB

A web browser provides a uniform user interface to different types of information. Making this interface universally accessible and more interactive is a long term goal still far from being achieved. Universally accessible browsers require novel interaction modalities and additional functionalities, for which existing browsers tend to provide only partial solutions. Although functionality for web accessibility can be found as open-source and free software components, their reuse and integration is complex because they were developed in diverse implementation environments, following standards and conventions incompatible with the web. To enable the integration of existing partial solutions within a mainstream web browser environment, we have developed a middleware infrastructure, AMICO:WEB. This enables browser access to a wide variety of open source and free software components. The main contribution of AMICO:WEB is in enabling the syntactic interoperability between web extension mechanisms and a variety of integration mechanisms used by open-source and free software components. It also bridges the semantic differences between the high-level world of web XML-based APIs and the low-level APIs of the device-oriented world. We discuss the design decisions made during the development of AMICO:WEB in the context of web accessibility, using two typical usage scenarios: one describing a disabled user using a mainstream web browser with additional interaction modalities; another describing a non-disabled user browsing in a suboptimal interaction situation

Video on the semantic web: experiences with media streams

In this paper, we report our experiences with the use of SemanticWeb technology for annotating digital video material.Web technology is used to transform a large, existing video ontology embedded in an annotation tool into a commonly accessible format. The recombination of existing video material is then used as an example application, in which the video metadata enables the retrieval of video footage based on both content descriptions and cinematographic concepts, such as establishing and reaction shots. The paper focuses on the practical issues of porting ontological information to the Semantic Web, the multimedia-specific issues of video annotation, and requirements for Semantic Web query and access patterns. It thereby explicitly aims at providing input to the two new W3C Semantic Web Working Groups (Best Practices and Deployment; Data Access)

Device Independent Multimedia Authoring

Also for multimedia, there is a need to create presentations in presentation-independent forms and have the final form(s) generated from the base document. We can input our expertise on the specific requirements for multimedia in automatic document generation. In addition, we have experience in processing multimedia documents in a Web context in general and related issues within SMIL 2.0 in particular. We can explain the use of alternative media for devices where text is inappropriate. In addition, different sorts of meta-data can be incorporated into a presentation-independent base document, and device/user-specific presentations can be generated from this base document, using the information captured in the meta-data. In addition, we can explain the advantages of incorpo

Configuring Semantic Web Interfaces by Data Mapping

We demonstrate how to develop Web-based user interfaces for Semantic Web applications using commonly available, off-the-shelf Web widget libraries. By formally defining the underlying data model that is assumed by these widgets, Semantic Web application developers can use familiar RDF constructs to map their own data to the model implemented by the Widgets. As an example, we briefly describe the interface model underlying our own framework, and provide concrete examples showing how it has been used to create Semantic Web applications in two different domains. We conclude by discussing the advantages and limitations of our approach

How Contentious Terms About People and Cultures are Used in Linked Open Data

Web resources in linked open data (LOD) are comprehensible to humans through literal textual values attached to them, such as labels, notes, or comments. Word choices in literals may not always be neutral. When outdated and culturally stereotyping terminology is used in literals, they may appear as offensive to users in interfaces and propagate stereotypes to algorithms trained on them. We study how frequently and in which literals contentious terms about people and cultures occur in LOD and whether there are attempts to mark the usage of such terms. For our analysis, we reuse English and Dutch terms from a knowledge graph that provides opinions of experts from the cultural heritage domain about terms' contentiousness. We inspect occurrences of these terms in four widely used datasets: Wikidata, The Getty Art & Architecture Thesaurus, Princeton WordNet, and Open Dutch WordNet. Some terms are ambiguous and contentious only in particular senses. Applying word sense disambiguation, we generate a set of literals relevant to our analysis. We found that outdated, derogatory, stereotyping terms frequently appear in descriptive and labelling literals, such as preferred labels that are usually displayed in interfaces and used for indexing. In some cases, LOD contributors mark contentious terms with words and phrases in literals (implicit markers) or properties linked to resources (explicit markers). However, such marking is rare and non-consistent in all datasets. Our quantitative and qualitative insights could be helpful in developing more systematic approaches to address the propagation of stereotypes via LOD

Hypermedia Presentation Generation on the Semantic Web

The research goal of the Multimedia and Human-Computer Interaction group at CWI is to investigate the automated generation of Web-based hypermedia presentations tailored to the abilities, preferences and platform of the user. This requires the description and processing of different types of information in order to assemble semantically annotated media items into a coherent presentation, i.e. a presentation that communicates the intended semantic relations to the user