XTM (XML Topic Maps) and Topic Maps for Portals
December 11, 2000
I first learned about Topic
Maps at XML99 a year ago. However, the concept has been kicking
around the SGML community for a number of years. This year, the vast
majority of the
Knowledge Technologies track was devoted to Topic Maps. Topic
Maps facilitate quick and accurate retrieval of information. They
build upon the semantics of RDF
and the syntax of XLink,
and can be used in a variety of ways, one of which is to foster
sophisticated navigation within a given site and across a much wider
web of "topic space".
Dianne Kennedy (InfoLoom Inc.), chairperson of XML 2000, has a
concise description of Topic Maps in her article, Topic Maps
Emerge as a Hot Topic, in which she writes: "Topic Maps are SGML
or XML documents that describe what an information set is about, by
formally declaring topics, and by linking the relevant parts of the
information set to the appropriate topics. Topic Maps may be included
within a document or be a separate document overarching an
information set. As such Topic Maps provide a navigation map, or
style sheet for navigation to the information set. Topic Maps are
usually thought to be "above" an information set and provide a
superimposed view that allows us to navigate the information set. A
topic map expresses one opinion about what the topics are, and which
parts of an information set are relevant to which topics. There is no
limit to the number of topic maps that can be created above the same
information set."
A special announcement of the completion of the XML Topic Maps (XTM) 1.0
specification was made at the XML 2000 conference. The spec was
completed as an ISO/IEC effort in roughly six months.
According to XTM
home page, "[The] structural information conveyed by topic maps
includes:
- groupings of addressable information objects around topics
(occurrences), and
- relationships between topics (associations).
A topic map defines a multidimensional topic space...."
As described in the abstract of the XTM 1.0 spec: "[The XTM]
specification provides a grammar for representing the structure of
information resources used to define topics, and the associations
(relationships) between topics. Names, resources, and relationships
are said to be characteristics of abstract subjects, which are called
topics. Topics have their characteristics within scopes: i.e., the
limited contexts within which the names and resources are regarded as
their name, resource, and relationship characteristics. One or more
interrelated documents employing this grammar is called a topic
map. TopicMaps.Org is an independent consortium of parties
developing the applicability of the Topic Map paradigm [ISO13250] to
the World Wide Web by leveraging the XML family of
specifications."
Note: XTM is currently not a W3C specification, although it is
an ISO spec. It is possible that XTM may eventually be submitted as a
W3C Note.
In a separate talk entitled Topic Maps for Enterprise
Information Portals, Norbert Mikula, CTO of DataChannel and Chair of the OASIS Technical
Advisory Committee, talked about XML-Based Portal
Solutions. His presentation discussed Topic Maps from an applied
and business- oriented perspective. Using the concept of enterprise
information portals (EIP) as an example, he explored impacts and use
cases of Topic Maps. EIP was shown to be useful in solving two key
business problems: finding the right information quickly and finding
the right person with a special role with respect to a topic
area.
Noteworthy Topic Maps resources include:
Tim Berners-Lee (W3C) and the Semantic Web
What Happened at XML 2000?
David Turner (Microsoft): SQL Server 2000 and XfA
|
eBook library