Wikipedia:Overcategorization

Categorization is a useful tool for finding and correlating articles. However, sometimes we tend to overcategorize; the more categories an article is in, the less meaningful all of them become. Hence, based on existing guidelines and WP:CFD precedent, this page lists types of categories that should be avoided. If created, categories of these types are very likely to be deleted.

General cases

Not objectively defined

Examples: Tall people, Notable architecture, Famous songs

It is vague how tall a person should be to be part of this category, and hence it is not a useful categorization. In general categories should never contain words such as "famous" or "notable"; it is assumed that if the subject is not famous or notable, it doesn't belong in a category.

Arbitrary inclusion limit

Examples: People over six feet tall, Villages with more than 10,000 inhabitants, Disasters with more than 5,000 casualties

There is no particular reason for choosing "six", "10,000", or "5,000" as cutoff points in these three cases. A village with 9,800 people is not meaningfully different from one with 10,100 people. A better way of representing this kind of information is to to put it in an article such as "List of villages in (locality) by size". Note that our software currently allows a table to be made sortable by any column. The obvious exception is categorizing by year, since making a category for each year is not arbitrary.

Non-defining or trivial characteristics

Example: People who own cats, Motorcycle riders, Blondes

We should categorize by what is actually important in a person's life, such as their career, origin and major accomplishments. In contrast, someone's tastes in food, their favorite holiday destination, or the amount of tattoos they have are trivial. Such information may be interesting to put in the article, but is not useful for categorization. If you could easily leave something out of a biography, it is not a defining characteristic.

Opinion on an issue

Example: People who like ice cream, Politicians who favor legalizing drugs

As above, holding an opinion is not a defining characteristic, and should not be a criterion for categorization, even if a reliable source can be found for the opinion. Categories such as "Republicans" should be reserved for people doing active work (direct or indirect) for the party, as opposed to merely voting for it.

Gender, race and religion

Example: Christian ice skaters, Female chemists

Generally, people should only be categorized by gender, race or religion if this has significant bearing on their career. For instance, in sports, Christian ice skaters are not treated differently from Jewish or Muslim ice skaters. Similarly, in chemistry, a person's actions are more important than their gender (and there is no separate Nobel Prize for female chemists).

See also: Wikipedia:Categorization/Gender, race and sexuality

Award winners and nominees

Example: Michigan Red Herring Award nominees

As a rule of thumb, if an award doesn't have an article, then a person should not be categorized by receiving it. It may nevertheless be useful to note the award in the article. Nominees should not be categorized, but put into a list instead. The sole exception to that is the Academy Awards, which is under debate.

Inclusion in a published list

Example: Top 40 songs

Magazines and books regularly publish lists of the "top 10" (or some other number) in any particular field. Such lists tend to be subjective and somewhat arbitrary, and as such don't make for meaningful categorization. Additionally, since there are many of such lists, creating categories for all of them would add needless clutter to all relevant pages. Some particularly well-known and unique lists such as the Forbes 400 may constitute exceptions, although creating categories for them risks violating the publisher's copyright.

Triple intersection

Example: Italian composers born in 1850

Many categories are an intersection of two traits, e.g. "Spanish architects". It is generally not useful to create categories as an intersection of three or more traits, as these tend to be overly narrow. Note that even intersections of two traits are not always useful if their main use is to split large categories.

However, note that e.g. "Italian-American" denotes a single trait of ethnicity, not two separate origins; and note that e.g. "Ohio American" is a redundancy since "people from Ohio" are an obvious subset of "Americans".

Subcategories creating large overlaps

Example: 1962 New York Yankees team roster, Members of United States 92nd Congress

Categories like this will likely add multiple categories to many articles, for instance if most of the 1962 team was also on the 1963 team. It is better to handle these with a single category, and create lists that detail the multiple instances.

Specific cases

Actors by film, or films by actor

Example: Starship Troopers actors, or Films starring John Travolta

Since most films have several dozen otherwise-unrelated actors, and most actors play in several dozen otherwise-unrelated films, these categories would add unnecessary clutter to all pages on actors and films. This information is better represented by including a list of actors in the film article, and vice versa.

In contrast, categorizing films by director is generally useful, because most films have only a single director, and directors tend to have their own styles.