# Chapter 1. What's in Wikipedia?
## What's in Wikipedia?

* Types of Articles
* Article and Content Inclusion Policies
** Core Policies: V, NOR, and NPOV
** Understanding the Policies
** Other Guidelines
*** Notability
*** Copyrighted Material
*** Non-encyclopedic Content
** What Wikipedia Is Not
* Non-article Content
** Types of Non-article Pages
** Namespaces
*** List of Namespaces
* Summary and What to Read Next

## Scope

Wikipedia is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. Even if you only read the titles of Wikipedia articles, it would take you most of a month, without a break, to scan all of them. If you tried the same with Microsoft Encarta, or any traditional encyclopedia, you could be done in about a day, with time left over to eat, shower, and take yourself to bed. Reading the full content of Wikipedia would take you well over two years, if you read continuously—and then you would have to start over, as most of the pages would have changed in the meantime.
There are well over two million articles in Wikipedia. And the site is still growing at an enormous rate, so this total will doubtless be much higher when you read this than it is as we write it (see Figure 1.1, “Wikipedia's growth over time”). By early 2008, the English-language Wikipedia was estimated to consist of over 960,000,000 words, which is equivalent to over 1,700 copies of War and Peace (itself about 560,000 words long in a standard English translation). On average, another 20 to 40 million words were being added each month, or 35 to 70 more copies of War and Peace—or one copy every 12 hours, all day, every day, continuously.
    Figure 1.1. Wikipedia's growth over time
This enormous growth has been occurring since Wikipedia began. Some more statistics show that the site has grown most rapidly since 2005, as Wikipedia's mainstream popularity took off:
* The site launched on January 15, 2001.
* It ballooned to 250,000 articles by April 2004, on the English-language site alone.
* It passed 500,000 English-language articles in March 2005.
* A year later, on March 1, 2006, the English-language Wikipedia surpassed the 1,000,000-article milestone.
* By late 2006, there were over 1.5 million English-language articles, with around 1,700 new articles being added each day.
* The article total surpassed 2,000,000 in September 2007.
* By August 2008, there were over 2,500,000 articles. At this point, articles were being created at a rate of 10,000 articles per week.
* During this same period, Wikipedias in other languages were also experiencing tremendous growth; see Chapter 15, 200 Languages and Counting for more on these projects.
Wikipedia has never had a target number of articles; any contribution is kept in the encyclopedia as long as it meets Wikipedia's standards. The average Wikipedia article is still quite short, say 500 words, but articles also tend to grow over time.
With well over two million articles in the English-language Wikipedia, topics include almost everything imaginable: from detailed explanations of basic science topics to equally detailed expositions of episodes of popular television shows. There are articles on railway locomotives, programming languages, people of all types, abstract concepts, and cities and towns all around the world. Finding out what's in Wikipedia is one of the great joys of exploring the site.

### What Is an Article?

An article, in this context, is defined as a Wikipedia page that contains encyclopedic information. Technically, the article count only measures pages of content that are not dead ends (which means they contain at least one internal link leading to another Wikipedia article) and are not redirects (pages that simply automatically take you to another article). The article count also ignores a great variety of other types of pages that are not devoted to content (administrative, internal, image description, and community pages, all described in detail in "Non-article Content" on Section 3.1, “Types of Non-article Pages”). Counting all these other pages brought the total Wikipedia page count to over 13,000,000 by mid-2008.
This first chapter will offer an introduction to the encyclopedia through the following approaches:
* Describing the content found in Wikipedia. (If you're overwhelmed by Wikipedia's labyrinthine setup, Chapter 3, Finding Wikipedia's Content will discuss good ways to navigate around the site and explain how to find content by searching and browsing.)
* Explaining the types of content the encyclopedia aims to include by outlining the criteria for topic inclusion, the style in which topics are covered, and other content policies. Once you understand something about the policies and guidelines that govern content, you can start to get a feel for Wikipedia's house style—the telling details that indicate whether an article has been worked on by good editors. (Chapter 4, Understanding and Evaluating an Article will explain in greater detail how to evaluate an article's quality.)
* Summarizing the parts of Wikipedia that do not consist of encyclopedia articles and explaining how to tell the difference between articles and other types of pages.
The basic information in this chapter will provide the foundation for understanding how to edit Wikipedia, described in Part II, and how to participate in the site's community, described in Part III.
Wikipedia covers every topic found in general encyclopedias, specialist encyclopedias, and almanacs, along with many topics not covered in any of these traditional references. This is possible in part because Wikipedia is not constrained by the economics of traditional publishing; it does not need to pay writers or spend money on paper. (Wikipedia is instead constrained by the judgment of its volunteers: It does not accept just any article. Several inclusion policies are enforced.)
    Note: The ultimate purpose of Wikipedia's community is to create and improve articles and to distribute them freely.

## Milestones

There has always been interest in Wikipedia's milestones—the moments at which the number of Wikipedia articles surpasses certain round numbers. Friendly betting pools developed around guessing the milestone date for a half-million and then a million articles. At this writing, the five million and ten million article betting pools are open for guessing the exact date when Wikipedia will reach these milestones. (The prize is widespread recognition of your remarkable guessing skills.) See Wikipedia:Pools.
The actual millionth article, created on March 1, 2006, was Jordanhill, an article about a railway station in Scotland. Hundreds of people counted down on the IRC channel and the wiki to see which of a flurry of new articles would be the one millionth article. Many editors waited anxiously for the opportunity to post; over one hundred articles were contributed during the same second. There was even major media coverage of the event; see "English Wikipedia Publishes Millionth Article". The two millionth article was created on September 9, 2007. Amid some confusion, the article El Hormiguero, about a Spanish TV comedy, was identified as probably being the two millionth article.

## Audience and Level

All articles should be clearly worded and accessible to a general readership, but Wikipedia also welcomes specialist articles that require a background in the topic to be fully understood. These articles should include context for the lay reader, however.
On rare occasions, two articles about a topic exist—an uncompromising article that provides a full picture and a more accessible "introduction" article for nonspecialists (for example, Introduction to entropy). See Category:Introductions.
Articles vary widely in length, detail, and comprehensiveness. Most of Wikipedia's articles begin their lives as stubs (very short summaries) and are gradually built into more comprehensive treatments by several editors. Stubs are incomplete—by definition, they lack something vital—but they are often useful and well written. Approximately 70 percent of Wikipedia articles are still classified as stubs.
The remaining 30 percent of articles (perhaps numbering over half a million) are more in-depth, comprehensive treatments of a subject. These may rival or go beyond the best work in traditional encyclopedias. A high-quality article includes numerous sources and references, pictures or diagrams, and a complete and clear explanation of the topic.
    [1] ^ This figure is based on size estimations at http://en.wikipedia.org/wiki/Wikipedia:Size_in_volumes, which also notes that Wikipedia is equivalent to 725 volumes of Encyclopaedia Britannica.