Organizing wiki pages
Organizing wikis is referred to 'wiki gardening.' As the number of items on a page grows, and individual items gain their own definition, they should be moved to their own page. Rather than creating many links to organize pages, categories are used. This way, all pages in a category can be included anywhere using a simple query. For an example, look at the Information by course, then look at its source.
Categories can be created "organically," and renamed as required. Categories are created in a hierarchical fashion, by referring to sub categories on a top level categories page.
Ontologies are an important concept in information design. They are the categories and properties (attributes) of information in a particular domain. For example, an ontology for CED might include a category of regions, and properties of economic factors.
When an ontology exists for your domain, your information can be related on a global scale, providing opportunities for examination, learning and collaboration.