Friday, 14 June 2013

Topic Maps

Topic maps are a form of XML: Extensible Markup Language. Their purpose, ultimately, is to make information more easily findable, and more authoritative.

Its History and Future

The method of the topic maps dates back to at least 1991, though their use has come a long way since then. The earliest use of such a form of information interchange was detailed in a publication entitled XML Topic Maps – Creating and Using Topic Maps for the Web: in the third chapter. In more recent years, the topic map has been standardized as a data model by ISO in 2006, and was also given XML-based serialization format, XTM 2. Currently a query language and a modelling language are in the progress of ISO standardization.

What makes up a Topic Map?

While plain XML is usually used for one of two purposes (either to structure an organization’s documents or to arrange an organization’s applications in such a way that they communicate with each other properly), topic maps exceed this. A topic map collects and compiles all the key concepts in a data set and ties it all together neatly, with references to outside information, by means of links through URLs.

For example, while plain language that details a hypothetical repair procedure in this way: “Fixing part A consists of steps X and Y”, a topic map takes a step back from the information itself and rather details the parts of the information and how they are connected. A topic map description of that same procedure would read something like: “Part A is of Type Q which is mentioned in sections Y and Z”. In a sense, the topic map helps the user to see the forest rather than the trees in the information architecture.

The information a topic maps represents is made up of 3 parts, sometimes referred to as the “TAO” of topic maps. Topics, which may refer to any person, place, organization or individual file; associations, which represent relationships between topics; and occurrences, which represent sources of information that are relevant to a particular topic.

A Wide Range of Applications

This form of representing data is seen by many as a liberation from the sometimes restrictive form of top-to-bottom information hierarchy that is dominant in most information indices. Topic maps allow for a more open form of data representation with overlapping hierarchies and rich cross-referencing by means of links. This openness has led the topic map to be most commonly used to build web sites that are entirely topic-map driven, so as to best use their info-finding benefits. This is certainly not the only use for them although it might appear the most obvious use. Topic maps can also be used as ways of managing information on content management systems rather than the traditional folder hierarchy system.

Topic Map Engines

Creating a topic map from scratch may seem daunting, especially for those uninitiated in the ways of XML. Fortunately, reinventing the wheel is unnecessary, because a few open source topic map engines exist to assist you in creating, maintaining and deploying your own topic maps and topic-map based applications and websites. Here are some examples of free engines you may want to check out: Ontopia, MajorToM, Ruby Topic Maps, tinyTiM and NetworkedPlanets Web 3.0.