Wikipedia:Viability of lists

Just because you can create something, doesn't mean you should. In order to keep Wikipedia from becoming an indiscriminate collection of lists, some measure of restraint should be taken before creating a list. This essay concerns list articles. Disambiguation pages and the like are a separate class of page with a completely different purpose than list articles and topics. Certain types of navigational lists, though, may be under the scope of this essay.

Article vs List
Since this essay focuses on the viability of lists, it is important to define what is and is not a list. According to Wikitionary, the best definition that first Wikipedia is "A register or roll of paper consisting of an enumeration or compilation of a set of possible items." While Wikipedia doesn't use paper, the basic premise is the same.

This is important because while an article by its nature must contain a large portion of prose, a list may or may not. What this means is that lists can be like List of counties in Alabama where beyond the lead, there is virtually no prose, List of battleships of Germany, where there is prose intersperced with charts throughout the article or List of Bleach characters which is a list entirely made of prose. In addition, lists need not start with "List of". Lists can be in other forms such as Timeline of evolution or not contain any indiciation within the title that it is a list such as Heroic Age of Antarctic Exploration. However, all of these share the common point of enumerating or compiling a set of items.

Finally while most lists use prefixes such as "List of", "Timeline of", "Chronology of", etc., they are not required to do so. With lower quality articles, a page it may look more or less like a stand-alone list, but a more complete high qualify version will show whether the content. Nintendo video game consoles may appear to be an article because the amount of prose, but to many it is a list.

Verifiability
Lists need to conform with Wikipedia's core policies, including verifiability and no original research. In addition, for lists one also have to show through reliable sources how multiple items are related; it is not enough to just group them together and say they are - that is original research.

Notability
While it is best to re-establish notability within the list, it is not always necessary. Some lists are notable because the topic itself is notable. If the topic is notable then a list dealing with the topic is notable and vice versa. the opposite is also true; if a topic does not meet the notability guideline, then a list on the topic is also not notable.

For more complex lists where there is a qualifier, such as List of birds of Canada and the United States other factors come into play.

Complex lists
While notability of a topic is clear for singluar criteria lists like List of birds, it becomes more difficult when qualifiers are made on these lists.

While it may be okay to say that if One Piece is notable then List of One Piece chapters and List of One Piece episodes as those are published material of the media franchise, it is unclear if List of One Piece characters would be, although there is widespread support (and also dissent) for this.

Other complex lists like location-based lists may depend upon how well the topic is likely to have serious study; the narrower the location, the less likely that is to happen. List of birds of Canada and the United States is a pretty broad region; List of birds of Missouri is smaller, but still large and thus likely to have enough content; List of birds of St. Louis is small, but might be viable as St. Louis is a notable city; List of birds of Forest Park, St. Louis is probably too small of an area to be viable. However, there are always exceptions for small areas like Birds of Yellowstone National Park.

Being discriminate
Just because a topic is notable, does not mean it needs a list. Common sense and consensus should prevail. A wing is a notable topic, but List of wings would not be an appropriate list because the topic is so broad and diverse it encompasses a subject too large to easily categorize.

In addition while a List of U.S. Presidents is a good list idea, a List of U.S. Presidents with brown eyes is not because the listing of U.S. Presidents is quite small and grouping people by their eye color is almost unheard of.

For stand-alone lists, the selection criteria should be clearly explained, both in the article's introduction to the list and also stated in the header of the talk page via Template:List criteria, which requires a link showing where consensus was established for the list criteria. Lists lacking adequate statements of list criteria can be tagged with Template:List missing criteria. If the criteria include an acceptable reference to Wikipedia, format it with Template:Self-reference link. Effective use of the criteria guidelines and these templates will help focus lists and prevent the accumulation of indiscriminate information.

Longest, biggest, highest
Wikipedia hosts a number of these types of lists which boast something to be "the xxx of" such as List of rivers by length. In many cases these items are likely to be documented somewhere specifically, however more specialized interest lists like List of manga series by volume count may not be. However, as Wikipedia is an paperless encyclopedia which covers different types of manga, such a list is reasonable to have since it has a clear objective and is both reasonably broad and discriminatory in its scope. By contrast List of coolest looking hubcaps is neither objective nor broad as while we have an article on hubcaps, we don't devote a multitude of articles to that.

In some cases it is impossible to gauge what belongs in a list even though it the criteria seem objective. A good example is List of cars by speed. Cars are certainly a well covered topic, however fastest moving cars has no clear criteria what goes in it. If it goes by top speed then List of cars by top speed is better. Does it mean acceleration? Again, List of cars by acceleration is better. There could also be other criteria such as top cruising speed.

Too broad
Some topics just aren't that viable because they would be either too broad or of little interest. These usually comes because the criteria for the list is extremely easy to accomplish that it is relatively commonplace such as List of students with perfect attendance. It is a clearly objective statement, relatively narrow focus (for a broad list), but the numbers of people who could qualify for this are extremely high when one takes into account the number of students worldwide. Finally, this is a relatively easy thing to accomplish. While a specific individual may not have or had perfect school attendance, numerous people do or did.

Neutrality
While List of U.S. Presidents is small, it is still long enough that it could theoretically be divided by a common item like party creating two lists: List of Republican U.S. Presidents and List of Democratic U.S. Presidents. However, just because it can be, doesn't mean it should be. Lists must also conform to neutrality and splitting an article like that could be seen as a point-of-view fork by trying to convey that the party affiliation of the President ties certain Presidents together and alienates them from others.

Spinout lists
Many list articles come about when a list grows too large and begins to dominate an existing article. When this happens editors usually create a separate article placing the info there. While there are many quality lists that emerge from this, there are many more that do not need to be split.

Before spinning out a list - or another article for that matter - because of the article's or section's size, consider editing the article to reduce unnecessary info or wordy prose.