Christiaan Fluit

Ontology-based information visualisation

The main contribution is to show how visual representations of information can be based on ontological classifications of that information. We first discuss the central role of ontologies on the Semantic Web. We subsequently outline our general approach to the construction of ontology-based visualisations of data. This is followed by a set of examples of ontology-based visualisations which all differ in interesting respects. We conclude with a brief discussion of related work.

Semantic desktop 2.0: the Gnowsis experience

In this paper we present lessons learned from building a Semantic Desktop system, the gnowsis beta. On desktop computers, semantic software has to provide stable services and has to reflect the personal view of the user. Our approach to ontologies, the Personal Information Model PIMO allows to create tagging services like del.icio.us on the desktop. A semantic wiki allows further annotations. Continuous evaluations of the system helped to improve it. These results were created in the EPOS research project and are available in the open source projects Aperture, kaukoluwiki, and gnowsis and will be continued in the Nepomuk project. By using these components, other developers can create new desktop applications the web 2.0 way.

Ontology-based Information Visualization

The Semantic Web is an extension of the current World Wide Web, based on the idea of exchanging information with explicit, formal and machine-accessible descriptions of meaning. Providing information with such semantics will enable the construction of applications that have an increased awareness of what is contained in the information they process and that can therefore operate more accurately. This has the potential of improving the way we deal with information in the broadest sense possible, e.g. better search engines, mobile agents for various tasks, or even applications yet unheard of. Rather than being merely a vision, the Semantic Web has significant backing from various institutes such as DARPA, the European Union and the W3C, which all have formed current and future Semantic Web activities.

Supporting User Tasks through Visualisation of Light-weight Ontologies

Since ontologies will be used to suport a variety of different tasks, and since experience from other fields has shown that visualisation techniques can be successfully used to support these tasks, this chapter investigates the use of ontology-based visualisation techniques for a variety of different tasks.

Ontology-Based Information Visualization: Toward Semantic Web Applications

This chapter has demonstrated an elegant way to visually represent ontological data. We have described how the Cluster Map visualization can use ontologies to create expressive information visualizations, with the attractive property that classes and objects that are semantically related are also spatially close in the visualization.

A topic-based browser for large online resources

The exploration of large information spaces is a difficult task, especially if the user is not familiar with the terminology used to describe information. Conceptual models of a domain in terms of thesauri or ontologies can leverage this problem to some extend. In order to be useful, there is a need for interactive tools for exploring large information sets based on conceptual knowledge. We present a thesaurus based browser that supports a mixed-initiative exploration of large online resources that provides support for thesaurus-based search and topic-based exploration of query results. We motivate the chosen exploration strategy the browser functionality, present the results of user studies and discuss future improvements of the browser.

XAROP: A Midterm Report in Introducing a Decentralized Semantics-Based Knowledge Sharing Application

Knowledge management solutions relying on central repositories sometimes have not met expectations, since users often create knowledge ad-hoc using their individual vocabulary and using their own individual IT infrastructure (e.g., their laptop). To improve knowledge management for such decentralized and individualized knowledge work, it is necessary to, first, provide a corresponding decentralized IT infrastructure and to, second, deal with specific problems such as security and semantic heterogeneity. In this paper, we describe the technical peer-to-peer platform that we have built and summarize some of our experiences applying the platform in case study for coopetitioning organizations in the tourism sector.