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This review highlights the problems with traditional document navigation and the need for improved reading and search facilities. It discusses the potential of hypertext and hypermedia solutions, with a focus on topic maps. It explains the structure, linking, indexing, and filtering capabilities of topic maps, showcasing their power in organizing and navigating information.
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Review of Topic Maps Luxemburg MR meeting Steven Depuydt Nov 22, 2002
Information • Problems • Getting lost in documents • Documents often too long • Often no (sufficient) navigation facilities, no links to related information • Reading = checking the contents, skimming, browsing,… before and while reading • Information overload • How to find what you really need? • Need for excellent search facilities Need to improve reading, change the way we read,...
Hypertext • Hypertext / Hypermedia as a solution: • Basic hypertext = nodes (information units) + links • Nodes = text, video fragment, sound,… • Links = relations between anchors (points in nodes) • Pro • Modularity = small manageable information units • Linking of documents = richer knowledge • Con • Disorientation (Where am I? Where I was? Where do I want to go?) • Cognitive overhead (Users get to much information that they cannot remember the route they took to their current position)
Hypertext • Natural hypertext navigation: • Links within one document or between documents • Advanced hypertext navigation features: • Table of contents • Maps • Indices • Search facility • Bookmarks • History list, … Solve most of the problems with hypertext, but often limited to one single document and each feature is often a separate application.
Topic Maps • A Topic Map structure is a high level structure that can cover all the previous navigation mechanisms (table of contents, maps, index, query engine, bookmarks, history list) mentioned. • From one single structure, all navigation features can be automatically derived • Topic Maps are a combination of (/ can be used for / are related to the following topics): • Structuring • Linking • Indexing • Filtering • Metadata • Searching • Clustering That’s why Topic Maps (are so powerful)!
Topic Maps • History • Started in the 90s • Davenport Group • Developers of the Docbook standard • Problem: merge of indices of different information resources. • ISO 13250 (SGML syntax) • XTM (XML syntax)
Topic Maps • Linking + Indexing
Topic Maps - Linking • Today’s links • Link information inside text objects
Topic Maps - Linking • Independent links • Link information outside documents (hytime, xlink)
Today’s links Inside Text based Single links One direction Hard to maintain Powerful ??? Independent links Outside Object based Multiple links Bi-directional Easier to maintain Powerful ! But, there’s more. Linking - Overview
Topic Maps - Indexing • Organising objects around keywords or topics (index, thesaurus, glossary...)
Topic Maps - Indexing • Next step: Linking of keywords (relations)
Topic Maps (linking + indexing) • The TAO of Topic Maps: Topics, Occurrences and Associations.
Topic Maps • TAO of Topic Maps • Topics (identified by their names) • Associations (describing relationships between topics) • Occurrences of topics (pointed to via locators)
Topic Maps • Topics • Topics have types (the class of which a topic is an instance, the ‘is a’ relationship) • Topics have identity • Topics characteristics • have 0 or more names • have 0 or more occurrences • play roles in 0 or more associations
Topic Maps • Example topics <topic id=“kul”><instanceof><topicref xlink:href=“#university”></instanceof><basename><basenamestring>Katholieke Universiteit Leuven</basenamestring></basename><variant><parameters><subjectIndicatorRef xlink:href=“…#psi-display”></parameters><variantname><resourcedata>KUL</resourcedata></variantname></variant></topic>
Topic Maps • Topic Occurrences • A collection of information relevant to a given subject (topic) • The link between the topic layer and the information pool • Occurrence types: definition, mention, article, picture, video, …
Topic Maps • Example occurrences<topic id=“kul”>…<occurs><instanceof><topicref xlink:href=“#definition”/></instanceof><resourceref xlink:href=“http://www.kul.be/kul_intro.htm”/></occurs> <occurs><instanceof><topicref xlink:href=“#logo”/></instanceof><resourceref xlink:href=“http://www.kul.be/kul_logo1.gif”/></occurs>
Topic Maps • Topic Associations • Describe relationschips between topics • Docarch is part ofKUL • Jan Engelen is head ofDocarch • Association types: part-of, head-of, is-in, born-in, … • Association members play roles: • Members: Docarch, KUL, Jan Engelen • Roles: department, university, professor
Topic Maps • Example associations<association><instanceof><topicref xlink:href=“#part-of”/></instanceof><member><rolespec><topicref xlink:href=“#university”/></rolespec><topicref xlink:href=“#kul”/></member><member><rolespec><topicref xlink:href=“#department”/></rolespec><topicref xlink:href=“#docarch”/></member></association>
Topic Maps application • Building blocks • Topic Map Authoring • As with XML, 2 steps: DTD and XML documents following the DTD • Step1: Topic Map design • topic types, association types, occurrence types, … (f.e.: City) • Step 2: Topic Map editing • ‘Real topics‘ (f.e.: ‘Paris’) • Topic Map Processor • Topic Map loading, storage and processing • Topic Map Viewer / Presentation • Different views (access) to different users