Subwiki:Categorization

Categorization involves the use of the in-built Category Feature offered by MediaWiki software to organize the material within a subject wiki.

Category as a list
A category is a list of articles sharing a common feature. An article on that list is said to be in the category. Each category has a page, called a category page, that provides the list along with general information about further resources on these pages (for instance, related categories).

An article can be in multiple categories. The categories in which an article is, can be found in a box at the bottom of the article.

Subject wikis convention: categories versus supercategories
The MediaWiki software powering subject wiki allows categories to be in categories, and calls a category inside another category a subcategory. We make use of subcategories in two ways.

In addition to the categories described above, which are lists of articles, the subject wikis also have certain other categories, which are lists of categories. These are called supercategories. A supercategory only contains categories but does not contain any articles.

Further, some ordinary categories in subject wikis have subcategories. For a subcategory of an ordinary category, the following convention is used: all articles in the subcategory are also in the main category.

Use of categories
Categories are used for two purposes:


 * Indicating the type of a definition, fact, or other article.
 * Indicating the topic area of a definition, fact, or other article.
 * Indicating the difficulty level of a definition, fact, or other article.

In other words, categories are used for clustering, either based on a logical notion of type, or based on other criteria.

Categories versus semantic MediaWiki
Categories are not used for relationships between multiple terms, facts and survey articles except when such relationships give rise to a strong cluster around a center. Thus, there may be a category titled variations of normality if there is a cluster of many variations of normality. However, there is unlikely to be a category of things stronger than normality if the relation is more symmetric and does not lead to clustering behavior.

For such relations, semantic MediaWiki is used. These allow relations with different tags between properties.