KCpedia:Categorization

From KCpedia

This article provides guidelines on creating and organizing categories.

Contents 1 When to use categories 1.1 Advantages of categories 1.2 Disadvantages of categories 2 Lists 2.1 Advantages of lists 2.2 Disadvantages of lists 3 Article series boxes 3.1 Advantages of article series boxes 3.2 Disadvantages of article series boxes 4 Categories do not form a tree 5 Cycles should usually be avoided 6 Guidelines for assignment of categories 6.1 Creating categories 6.2 Creating subcategories 6.3 Making groups of subcategories 6.4 Category membership and creation 7 Category naming 8 Categories requirements and usage 8.1 User browsing 8.2 Links to categories 8.3 Redirected categories 8.4 Category sorting 8.5 Year categories

When to use categories

Every page in the article namespace should belong to at least one category. Categories should be on major topics that are likely to be useful to someone reading the article.

Article: Philander Chase

Useful category: Category:Presidents

Not useful: Category:Presidents whose first name starts with P

Questions to ask to know 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 it's there? 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 member of the Class of 2003 is categorized in the Category:Class of 2003 category, which is in turn categorized in Category:Classes.

An article will often be in several categories. Restraint should be used, however — categories become less effective the more there are on a given article.

An article should not be in both a category and its subcategory, for example Microsoft Office is in Category:Microsoft software, so should not also be in Category:Software. Articles with the same name as the category should be in both the category with the same name and the higher level category. The category with the same name will also be in the higher level category. Both the article and the category will be listed in the higher level category. For an example Kansas City Chiefs contains Category:Kansas City Chiefs in addition to that category's parents, Category:National Football League teams, Category:Kansas City sports, Category:Dallas sports and Category:American Football League.

Categories appear without annotations, so be careful of Neutral Point of View when creating or filling categories. Unless it is self-evident and uncontroversial that something belongs in a category, it should not be put into a category.

Advantages of categories

1. Auto-linking. Create a link to a category on an article page, and a corresponding link to that article will be visible on the category page.
2. Multi-directional navigation. A category can contain multiple subcategories, and can also be part of several categories.
3. Categories are good for exploratory browsing of KCpedia.

Disadvantages of categories

1. Alphabetical order only (though you can control the alphabetization). Cannot be organized into sections and subsections on a single page, each with appropriate prefatory comments.
2. Listings cannot be annotated (e.g. length of a river).
3. They cannot contain invisible links to talk pages, which cause edits to those pages to appear when the user clicks on "related changes". (Thus: [[Talk:ABCology| ]])
4. Red links to not-yet-existing articles cannot be added to categories.
5. Cannot include alternative names for the same item.
6. Newbies do not understand how to add an item, how to link new categories into existing schemes, or Point of View concerns.

Lists

Lists are manually created and maintained pages that collect related items for easy browsing and launching to other articles.

Advantages of lists

1. Lists can be annotated. For example, a list of soccer world championship teams can also list when the championship was won.
2. Lists can include items for which there are no articles (red links); categories can only list things for which there are articles, unless stubs are created.
3. List items can be sorted using a variety of methods. An article can be listed several times or in different ways in the same list, or shown both in its major category as well as in several different subcategories, without cluttering the article with crossreferences.
4. Lists can link to items inside other articles.

Disadvantages of lists

1. Not auto-linked, as categories are.
2. May be redundant with categories if not formatted or annotated.
3. Longer lists may be a subject of spam and vandalism.
4. Lists are easily edited by newbies who are less familiar with KCpedia quality guidelines.

Article series boxes

Article series boxes (or navigational templates) are boxes with links to other related articles. Examples include presidents of the United States, movies in the Friday the 13th Series, or Narnia books. They may be used for small and more or less complete sets. The importance of the subject matter is not a consideration.

A series should have some ordering, whether chronological or otherwise. Alphabetical order is not preferable, as categories naturally arrange articles alphabetically, making a series box redundant. It is not enough that it is possible to organize the elements of a series in a some structure — that structure should itself be useful. For example, a box for characters from Buffy the Vampire Slayer by the order of listing in the opening credits is an ordering but is not useful, because it is unlikely that people would actually want to read the articles in that order. A category should be used instead.

As with categories, all the articles in a box should substantially deal with the subject of the box.

• Is the subject of this box something that would be mentioned on every article in the series?
• Is a given article in the series likely to mention the article before or after it in the series outside of the box?
• Are the elements of the box all going to generate articles substantial enough that the box will not look like an unmanageable blight on an otherwise tidy computer monitor?

If the answer to any of these questions is "no", a category or list is probably more appropriate.

If an article has more than one series box, it may be appropriate to convert some or all to categories.

Advantages of article series boxes

1. Provide a consistent look and navigation system for related articles (though not between different topics — there is no standard format).
2. Faster to navigate than a category.
3. Give immediate information to equivalent elements
4. For presenting a series of articles in a chronological order, series boxes are often most appropriate.

Disadvantages of article series boxes

1. Often replaceable with a category. It can be difficult to give more detail than a category can give without the box becoming unmanageably large.
2. Article series boxes are often considered unsightly.
3. Often inadvertently push a Point of View — suggesting that one aspect of a topic is more important than others, being used to advertise obscure topics in prominent places, or asserting project proprietorship.

Categories do not form a tree

Each Wikipedia article 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 tree structure, but a more general directed acyclic graph.

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.

Cycles should usually be avoided

Although the MediaWiki software does not prevent cycles (loops), these should usually be avoided.

Guidelines for assignment of categories

Creating categories

Creating a category is as simple as adding a soft link to the appropriate article in the Category: namespace; for instance, to add Philander Chase to the "Presidents" category, you would edit the article and enter [[Category:Presidents]] at the bottom. Although the link will not appear in the article text, a page called Category:Presidents will automatically list alphabetically all articles that contain the [[Category:Presidents]] link. The appeal of categories is that unlike lists, they update themselves automatically, and that one can use them to quickly find related articles. However, categories are not a substitute for lists, and you will find that many articles belong to both lists and categories. You may see some inconsistencies when first creating the category: it may alternate between appearing empty and appearing with your first additions. It will probably correct itself in a few minutes.

Note that, although "uncreated" categories will correctly list articles that have been assigned to them, the category page itself does not exist until it is manually created. The easiest way to create the category page is to follow the edit link from an article and add a parent category and a category description as explained below.

Creating subcategories

Create subcategory pages by putting the name of the parent category on a category page that you would like to be the subcategory. Child categories (subcategories) are created by putting [[category:parent_category_name]] on the lower-level category pages. For example, on a (sub)category page called category:Roses you put [[category:Flowers]], Roses becomes a subcategory of Flowers.

When adding an article to a category, or creating categories, one should be careful to use the correct categories and subcategories. Horizontal categorization, directly below, refers to placing an article in the correct category while vertical categorization refers to placing an article in the correct subcategory.

When assigning an article into categories, try to be thorough in a "horizontal" sense. The topic may be associated with a geographic area, a historical period, an academic subfield, a certain type of thing (like a food or an ornament), and/or a special interest topic (like Roman Empire or LBGT). You might need to poke around the category hierarchy a bit to find the right place. Try searching for articles similar to the article you are categorizing to get ideas or to find the most appropriate place. (For instance, '1990' is more correctly in 'Category:Years' rather than 'Category:Places'.)

In the "vertical" dimension, you should probably be more frugal. A good general rule is that articles should be placed in the most specific categories they reasonably fit in. For example, Queen Elizabeth should not be listed directly under People, but 'Category:Monarchs of the United Kingdom' might be a good place for her. We know that all Queens of the United Kingdom qualify as Famous Britons and as Royalty, and all of those folks qualify as People. But sometimes there's a good reason to assign an article to two categories, one of which is a direct or indirect subcategory of another.

Whatever categories you add, make sure they do not implicitly violate the neutral point of view policy. If the nature of something is in dispute (like whether or not it's fictional or scientific or whatever), you may want to avoid labelling it or mark the categorization as disputed. Most categorizations are pretty straightforward, though.

Making groups of subcategories

Categories can only list 200 entries at a time. When there are more than 200 entries, only the first 200 will be displayed. To make it easy to navigate, add a TOC (table of contents). TOCs are added by typing:

{{CategoryTOC}} - which adds a complete TOC (Top, 0 - 9, A-Z)

{{CatAZ}} - which adds a TOC without numbers. This is for categories with members that only start with letters.

When a given category gets crowded, also consider making several subcategories. Group similar articles together in a meaningful and useful way that will make it easy for readers to navigate later. Remember that several subcategorization schemes can coexist (for example, if Category:Presidents gets too big, you don't have to choose between subdividing it by function or subdividing it by platform, you can simultaneously subdivide it in both ways).

A set of related categories often forms a hierarchy or a nexus. This can take several different forms, all of which are welcome and encouraged:

• A taxonomic grouping. For example, Category:South Asian countries is part of a geographical hierarchy. Category:Academic disciplines catalogs divisions between fields of study.

• A functional grouping. Examples: Category:Ancient Rome, Category:World War II, and Category:Commercial item transport and distribution. These bring together articles and subcategories from different fields or taxonomies (history, war, culture, people, companies, industries, technologies) that have an interesting common thread.

• Hybrid forms. For example, Category:Art is both part of the taxonomy of Category:Academia and a cross-reference point for lots of things that have little in common except that they have something to do with art.

• Offshoot forms. For example, Category:Film stubs contains subcategories of Category:Comedy film stubs for comedy films, and Category:Drama film stubs for drama films.

Category membership and creation

When writing the description for a category, give it a parent category. In fact, you should try to give it at least two parent categories. For example, Category:British writers should be in both Category:Writers by nationality and Category:British people. A few categories do only merely subdivide their parent category, but unless the parent category has many potential articles under it, or many potential subdivisions, if you can't think of a second parent category, it might be a better idea to fold your smaller category into the parent.

Category naming

Categories follow the same general naming conventions as articles, for example do not capitalise regular nouns. For specific conventions related to categories, see KCpedia:Naming conventions (categories).

Categories requirements and usage

User browsing

Categories (along with other features, like cross-references) should help users find the information they are looking for as quickly as possible, even if they don't know that it exists or what it's called.

Links to categories

You can create a link to a category page without adding the page to that category by using a colon before the word Category. Example: [[:Category:Presidents]] appears as Category:Presidents.

Redirected categories

Although it is possible to attempt to redirect categories by adding a line such as #REDIRECT [[:Category:Automotive technologies]] to a category, it is not generally recommended because of limitations in the mediawiki software. Categories "redirected" in this way do not prevent the addition of articles to the redirected category. Articles added to the "redirected" category do not show up as in the target category. Until these issues are addressed (in future versions of the software), #REDIRECT should not be added to category pages.

Category sorting

Contrary to some expectations, text after a pipe ("|") in a category link is not used in place of the category text. Rather, this text is used as the sort key on the category page itself. However, again contrary to expectations, that sort text is not displayed.

For example, the Category:Three-digit Interstate Highways uses this property to sort secondary interstates by their primary. That is, the category link in the article for Interstate 190 (Illinois) is [[Category:Three-digit Interstate Highways|90-1 Illinois]]. This causes "Interstate 190 (Illinois)" to be listed right after "Interstate 189" and right before "Interstate 290 (Massachusetts)" under the heading "9" in the category page.

This feature is very useful for categories in which:

• the entries are people, in which case sorting by last name is preferable (example: Category:Presidents).
• variations in the naming of entries causes inconsistent sorting (example: List of counties in Nebraska, List of counties in Montana, but List of Nevada counties in Category:Lists of U.S. counties).
• the logical sort order is not alphabetical (example: individual month articles in year categories such as Category:2004, using e.g. the sort key "*2004-04" for April).

Using this method to sort category entries is sometimes informally referred to as the pipe trick. However, this use of the pipe character is very different from the original Wikimedia pipe trick which allows one to easily hide parenthetical disambiguation in links.

It is possible to force an article or subcategory to the top of the list by using a non-alphanumeric character as the first after the pipe. For example, using [[Category:Ford| Ford Motor Company]] (note the space) or [[Category:Ford|*Ford Motor Company]] would force that article to be displayed before all the others.

Year categories

In categories which are years, such as Category:2004, special sorting guidelines apply:

• Entries should generally be sorted by topic, so the article 2004 in film, for example, would contain the category reference [[Category:2004|Film]] while 2004 Canadian budget would contain the reference [[Category:2004|Canadian budget]]; List of religious leaders in 2004 would contain [[Category:2004|Religious leaders]].
• The article about the year itself, 2004, should be sorted first among all articles by using [[Category:2004|*]].
• Articles for individual months, such as October 2004, should be sorted chronologically in the first section on the category page, in this case using [[Category:2004|*2004-10]].