ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in the development of International Standards through technical committees established by the respective organization to deal with particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
ISO/IEC 13250-1 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information Technology, Subcommittee SC 34, Document Description and Processing Languages.
The topic maps standards enable users to answer two fundamental questions:
Examples of where topic maps have been used include:
Navigational tools such as indexes, cross-references, citation systems, or glossaries for information systems
Thesaurus-like interfaces to corpora, knowledge bases, etc.
Views of information systems that are filtered on the basis of language, security criteria, or any other useful basis
Providing unstructured information resources the appearance of structure for navigation or for use with other structured information resources
Providing context for subjects and relationships between subjects. (Context can be used to address the polysemy problem faced by WWW search engines.)
In order to have interchangeable answers to the questions of subject identity and co-location, the topic maps standards specify an XML syntax and processing model that standardizes a representations of subjects (topics), relationships between subjects (associations) and information about those subjects (occurrences). Beyond the basic syntax and data model, alternative representations (syntaxes) are also defined along with query and constraint languages.
Every choice of how to identify a subject and the basis for co-location of necessity excludes other, equally valid choices to answer those questions. To enable the future development of other interchangeable answers to those questions, a model with minimal ontological commitments that specifies a path language for the query and contraint language is also defined.
Topic maps, at their best, represent a user's knowledge of a domain. As such, they can capture human judgments about the identity of subjects, relationships between subjects, as well as other nuances that escape the notice of non-human systems.
The following are within the scope of this part of ISO 13250:
A description of the parts of ISO 13250;
A description of the relationships between parts of ISO 13250;
A description of the general purposes of ISO 13250.
This International Standard does not require any particular model for processing of topic maps.
Except as required or disallowed by any particular part of this Standard, any scheme may be used for addressing information objects.
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC 13250-2, Topic Maps — Data Model
ISO/IEC 13250-3, Topic Maps — XML Syntax
ISO/IEC 13250-4, Topic Maps — Canonicalization
ISO/IEC 13250-5, Topic Maps — Reference Model
ISO/IEC 13250-6, Topic Maps — Compact Syntax
ISO/IEC 13250-7, Topic Maps — Graphical Notation
ISO/IEC 18048, Topic Maps — Query Language
ISO/IEC 19756, Topic Maps — Constraint Language
ISO/IEC 29111, Expressing Dublin Core Metadata using Topic Maps
ISO/IEC 13250-1 provides a brief overview of topic maps. It also provides a short description of each part of ISO 13250 and the relationships between those parts.
ISO/IEC 13250-2 specifies a data model for topic maps. The standard model for topic maps, that is topics, associations and occurrences is formally defined in this part. Topics represent subjects, whose relationships with other subjects are defined by associations. Occurrences represent both the presence of subjects in information resources as well as additional information about a subject.
The data model uses the W3C infoset formalism to describe topic maps and constrains their interpretation, using prose. It also defines rules for merging topics and other information objects as well as the processing that follows that defined merging process. There are a number of fundamental subjects for topic maps that are defined by the data model. The data model notes but does not describe or constrain additional merging operations as being possible for any topic map. (See ISO/IEC 13250-5 for merging beyond the data model.)
The data model defined by 13250-2 underlies 13250-3, -4, -6, -7 and is used by ISO/IEC 18048 Topic Maps Query Language (TMQL) and ISO/IEC 19756 Topic Maps Constraint Language (TMCL).
ISO/IEC 13250-3 defines an interchangeable syntax for topic maps. The syntax is specified using RELAX-NG and its interpretation is constrained by ISO 13250-2. The use of XML along with the data model (ISO/IEC 13250-2) insures a level of interchangability between topic map applications but does of necessity constrain the tests for subject identity.
Historically speaking both the original topic maps syntax (HyTime) and the later XTM 1.0, were defined prior to the development of a data model (ISO/IEC 13250-2) or the more abstract reference model (ISO/IEC 13250-5). Future revisions of the syntax will be guided by the respective models.
ISO/IEC 13250-4 defines transformation of an an instance of the Topic Maps Data Model (ISO/IEC 13250-2) into an instance of the XML Infoset model.
The problem that is solved by this part is the comparison of the results of two or more topic maps engines on a single instance of topic maps syntax as defined by ISO/IEC 13250-3. It is true that the results of processing a single topic map by two topic map engines could be compared by a human user, that process would be error prone and not as complete as a comparison of all aspects of the processing of a topic map. This part specifies the sort order of items in the infoset representation and other matters to facilitate the task of comparison.
ISO/IEC 13250-5 defines an abstract model of topic maps with minimal ontological committments that supports the definition of path languages.
Known as the "reference" model, this part is a continuation of the recognition in the data model that not every basis for merging can be specified by a standard. It defines a formalism for describing topic maps models, such as ISO/IEC 13250-2 and the requirements for disclosure of such models.
This part defines a minimal model that enables the creation of a path language for ISO/IEC 18048 Topic Maps Query Language (TMQL) and ISO/IEC 19756 Topic Maps Constraint Language (TMCL).
ISO/IEC 13250-6 defines a compact syntax as an alternative to the more verbost XML syntax defined in ISO/IEC 13250-3.
XML syntax is very verbose and has been a source of difficulty in both gaining an overview of topic maps during construction, not to mention being tiresome to type. The compact syntax is the topic maps attempt to solve both of those issues. The processing of this syntax is identical to that of ISO/IEC 13250-3 as defined by ISO/IEC 13250-2 (Topic Maps Data Model) and for purposes of ISO/IEC 13250-4 (Topic Maps Canonicalization).
ISO/IEC 13250-7 defines a graphical notation for the representation of topic maps for use in designing, explaining, teaching or other circumstances where a non-syntax representation of a topic map is deemed useful.
The relationship of each part and how they fit together is shown in figure 1.
Figure 1 — Relationship of Topic Maps Standards
TMDM: defines topic map constructs and rules for those constructs
TMDM provides the foundation for the syntaxes and notations defined in Parts 3 XML Syntax (XTM), Part 4 Canonicalization (CXTM), Part 6 Compact Syntax (CTM), and Part 7 Graphical Notation (GTM), and ISO/IEC 18048 Query Language (TMQL) and ISO/IEC 19756 Constraint Language defined in accompanying standards.
TMRM: has three parts: formal model; path language; constraints on models
TMDM: uses the TMRM as a formal model and constraints on model (but not the path language)
TMCL follows the TMDM for topic map constructs and their rules but is not limited to those rules and uses the TMRM for a path language
TMQL depends on TMDM for topic maps constructs and their rules but is not limited to those rules and uses the TMRM for a path language
Topic Maps can identify subjects robustly and connect them with related subjects. As a result Topic Maps can solve synonym, homonym and polysemy problems. Topic maps can also represent the context in which subjects take on the meaning.
Topic Maps has two key strengths;
A flexible and intuitive knowledge model
A robust model of identity
In consequence Topic Maps provides the ability to control infoglut and share knowledge by connecting any kind of information from any kind of source based on its meaning.
Many cool things become possible with Topic Maps;
Classifying and Organizing
Querying (Adding semantic precision)
Navigating (Semantically and multiview point)
Filtering and Segmentizing (Capturing context)
Visualizing
Merging
Topic Maps can be used for many different purposes in industry, public sector, and academia. The principal applications are in semantic indexing, knowledge management, e-learning, information integration, etc.
Semantic Indexing
The volume of accessible information is exploding at an exponential rate. Search engine results are symptons of and not solutions to that problem. Topic maps offer:
Subject-based organization (everything organized around topics)
Associative model (very intuitive navigation)
Structured queries (adds more power to full-text search)
Examples of the semantic indexing applications are as follows:
Taxonomy management
Metadata management
Semantic portals
Every organization faces the challenge of the managing knowledge of its staff. Capturing and sharing knowledge that knowledge is a key factor of organization's success. Topic Maps provides ideal solution for this problem for the following reasons:
It captures knowledge as expressed by people
The resulting topic maps can be merged
They are based on an International Standard.
Examples of the Knowledge Management are as follows:
Business process management
Product configuration
Business rules management
IT asset management
Manufacturing asset management
Intelligence gathering and analysis
e-Learning
Knowledge is at the core of e-Learning. Computers support the acquisition of knowledge by humans. Topic Maps provides an excellent model to capture knowledge acquisition by:
Capturing what the pupil has learned
Structuring eLearning systems
Organizing school and university curricula
And enabling the merging of topic maps built for such resources.
Information Integration
Information is often spread across multiple systems. Topic Maps provides a single point of access to all information. Topic Maps does not require costly migration and re-engineering of existing content.
Very flexible data model, in concrete terms, Hierarchical (XML), relational (RDBMS), associative (RDF) data can be easily mapped to topic maps
Topic maps can be merged
Topic maps can be filtered
ISO/IEC 13250:2003, Topic Maps, 2003, http://www.y12.doe.gov/sgml/sc34/document/0322_files/iso13250-2nd-ed-v2.pdf
XTM1.0, XML Topic Maps (XTM) 1.0 Specification, Steve Pepper, Graham Moore, TopicMaps.Org, 2001, http://www.topicmaps.org/xtm/1.0/