Introduction

Quote, Source: Unknown

A book without an index is like a country without a map.

Maybe, for some of you, it is a challenging experience of driving from A to B without a map, but there is no doubt when the destination is to arrive as quickly as possible some kind of map is indispensable.

Similary, if you are looking for a particular piece of information, there is plenty of it on the web. But it is getting more and more important to find it fast. The average web user will usually undertake a multitude of searches, often without retrieving any meaningful result. What we need is a common way to structure information.

A new technology, known as topic maps has emerged to address the problem of mastering a huge number of information resources.

What is the background of topic maps?

The idea is, that, whenever somebody is having some expertise in a particular area (a theme), the author will denote (a part of) his knowledge in form of a so called topic map. This topic map may consist of as many topics he wants to put in; topics which might be important in terms of the original theme and also other, less related topics. How much information the author wants to provide, how deep he wants to delve into the given theme, is entirely up to him. The number of topics will ultimately determine the size and complexity of the topic map.

The interesting property of topic maps is, that some of these topics within a topic map can be in a relationship (associations) with each other. And, topics can play different roles in different associations. Topics can also contain any number of external references, such as web pages, which supposedly elaborate on a specific topic.

Topics have references to objects and concepts.

What do we need to create a topic map?

• Step 1: We need to define the theme which should be covered.
• Step 2: Then we collect as many topics as we can find which are relevant for the theme together with other external information resources, such as web sites (so-called occurrences).
• Step 3: And finally, we have to think about relationships between the collected topics (so-called associations).

Defining a theme

In our running example our topic map will cover general information about Bond University from a student's perspective.

The topic map itself can be defined via an XML document containing all relevant information:

<?xml version="1.0"?>
<topicMap id="bond-uni"
          xmlns       = 'http://www.topicmaps.org/xtm/1.0/'
          xmlns:xlink = 'http://www.w3.org/1999/xlink'>

<!--

    The map contains basic information about Bond University.

    More comment and nice description goes here, maybe also
    author information.

-->

.... here my topics and my associations go ...

</topicMap>

Like all XML documents, a topic map document (XTM) starts off with a header specifying the version of XML, followed by the topicMap tag (which declares some namespaces which we ignore here). The <!-- .... --> can contain any comment the author would like to provide.

After that, any number of topics and associations can be added to this map. The sequence of these declarations does not matter.