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PESWiki:Category schemes

Lasted edited by Andrew Munsey, updated on June 15, 2016 at 1:47 am.

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This article provides guidelines on creating and organizing categories. For detailed technical information on how to use categories, see There was an error working with the wiki: Code[2]. For everything you ever wanted to know about categories, see the There was an error working with the wiki: Code[3].

When to use categories

Categories (along with other features like cross-references, lists, and infoboxes) help users find information, even if they don't know that it exists or what it's called. Every page in the article namespace should belong to at least one category. Categories should be major topics that are likely to be useful to someone reading the article. Questions to ask to determine whether it is appropriate to add an article to a category:

If the category does not already exist, is it possible to write a few paragraphs or more on the subject of the category, explaining it?

If you go to the article from the category, will it be obvious why the article was put in the category? Is the category subject prominently discussed in the article?

If the answer to either of these questions is no, then the category is probably inappropriate. Note that it is always appropriate to add articles to categories that fit into well established taxonomies. For example, every article about a magnetic engine is categorized in some There was an error working with the wiki: Code[4] category, which is in turn categorized in Category:magnetic engine by inventor.

Some general guidelines

#Categories are mainly used to browse through similar articles. Make decisions about the structure of categories and subcategories that make it easy for users to browse through similar articles.

#An article will often be in several categories. Restraint should be used as categories become less effective the more there are on any given article.

#Articles should not usually be in both a category and its subcategory. However there are occasions when this guideline can and should be ignored. See #5 for another exception. For more about this see There was an error working with the wiki: Code[5]

#Check to see where siblings of the article reside. If there are few if any articles in a category, the article probably belongs in one of the subcategories.

#Articles should be placed in categories with the same name. However, the article and the category do not have to be categorized the same way. The article can also be placed in categories populated with similar articles. The category can be put into categories populated with similar subcategories.

#There are often occasions when articles might ideally be moved from a category to two or more of its subcategories, but not all of the subcategories exist. In such cases consider creating the additional subcategories, but if you decide not to do so, leave the articles in the parent category for the time being.

#Bend the rules above when it makes sense, but only if no other solution can be found.

#Categories appear without annotations, so be careful when creating or filling categories. A list might be a better option.

#If you don't know where to put an article don't worry about it. Instead of adding a category, use the uncategorized tag to bring attention to the article. Editors who love to categorize articles will find a good home for your article.

Categories vs. Lists vs. Info boxes

For alternative methods of grouping articles, and the circumstances in which they should be used, see There was an error working with the wiki: Code[6].

Categories applied to articles on people

A separate wikipedia page There was an error working with the wiki: Code[7] was created to help you in designing, applying and checking categories that are used for articles on people.

Categories do not form a tree

Each page can appear in more than one category, and each category can appear in more than one parent category. Multiple categorization schemes co-exist simultaneously. In other words, categories do not form a strict hierarchy or There was an error working with the wiki: Code[8], but a more general There was an error working with the wiki: Code[9] (or close to it see below). Nevertheless, parts of the category graph will be tree-like, and it may be convenient to think of parts of the category graph as being like multiple overlapping trees. When applying the guidelines above, consider each tree to be independent of the overlapping trees. A person browsing through a hierarchy should find every article that belongs in that hierarchy. This can lead to a good deal of debate as to what the hierarchies actually are. To clarify the structure of the hierarchy and help people browse through it, you can add a classification to each category. For more about this, see There was an error working with the wiki: Code[10].

Cycles should usually be avoided

Although the software does not prevent There was an error working with the wiki: Code[1] (loops), these usually should be avoided. Cycles can be confusing to some readers, they can challenge some automated searching processes and they can grow quite large. However, acceptable loops also exist. Self-referencing systems such as the There was an error working with the wiki: Code[11] fields naturally create cycles that provide many examples. This type of cycle involves making a category one of its own subcategories. Another type of cycle involves making two categories subcategories of each other. Loops such as these can be avoided by linking the categories manually to each other by adding "See also:There was an error working with the wiki: Code[12]" to each category page.