Categories are defined as classifications of related nouns and ideas that can be sub-divided into further categories and concepts. In the example branch, the concept of insects belongs to the category of zoology , which is a part of the more general category of biology , which is part of the even more general category of science and technology . Since concepts and categories are organized from general to specific, specifying broad themes in a query usually returns more documents than specifying more specific themes. Concrete and Abstract Concepts Concepts are leaf nodes in the knowledge catalog and can be associated with any level of category. Concepts can be either concrete or abstract.
Concrete concepts are ideas founded in the real world, usually described by nouns or noun phrases.
Examples of concrete concepts are jazz music and football . Abstract concepts are ideas such as happiness or success, usually described by abstract nouns. For example, if a news article was about the success of a famous football player and the article used words and phrases that described success, ConText might attach a theme of success to the document. Likewise, a news article describing a Christmas celebration might have a theme of happiness attached to it. Do not confuse with literary interpretation the way in which ConText attaches abstract concepts to documents.