What is ontological markup?

Metadata is simply information about information. Consider the statement: “A cat is a mammal.” Metadata for this statement might include:

• The statement is a complete English sentence.
• The statement is a fact — it is verifiable as true of false.
• The statement is a part of a biological taxonomy.
• The statement is used in an example of metadata in the DoH FAQ.

A popular method of representing metadata in modern computer science is extensible markup language (XML). This page, for example, is marked-up with a language that describes the display semantics so that <i>italic text</i> is displayed as italic text.

Ontologies are simply systems of metadata that focus on contextualizing data within a particular domain. It describes how information relates to other pieces of information. For example, to say that “A cat is a mammal” is a complete English sentence relates it to a set of known rules for constructing English sentences.

There is quite a bit of interest currently is generating a complex semantic web of ontological documents. The Ideapool project doesn’t focus on the distribution of any particular structure of documents beyond XML.