Wikipedia:Assessing reliability

Number of Sources

At the bottom of a good article, a section, usually called "References" or "Notes", will list sources that were used in writing the article. If this list is extensive the article is generally reliable.

Articles of high reliability will often contain both online sources (freely accessible via the Web) and offline sources (books or scholarly articles). The presence of online sources makes it easier for users to verify factual accuracy, whereas the presence of offline sources may be an indicator of thorough research.

Some examples of good reference lists include the articles Albert Einstein and Facebook.

Reliability of sources

Particularly if there are few sources listed, it is a good idea to scan those sources to see if they are reliable. Unreliable sources include most blogs and personal websites, although some of these are reliable. Reliable sources include most newspaper and magazine articles, online encyclopedias, and other professional publications such as books. Sources do not need to be online to be cited. See Wikipedia:Evaluating sources for more information on determining reliable sources.

Inline citations

In order to verify specific facts and controversial statements, inline citations are used to match sources in the reference list with facts in the article (Example 1).

On the other hand, inline text is also used to mark facts where verifiability is needed (Example 2) and where it is suspected that a statement is original research and is not verified by any source (Example 3). When you see these, it is a warning that the specific fact is unverifiable. On the other hand, it means that contributors of the article are keeping verifiability in mind.

Verifiability tags

The most obvious sign of verifiability problems is when an article is tagged for verifiability issues.

Examples

The following are some verifiability tags (templates) used on articles. More can be found here.

{{unreferenced}} links talk edit	This article does not cite any sources.
{{more citations needed}} links talk edit	This article needs additional citations for verification.
{{no footnotes}} links talk edit	This article includes a list of references, related reading, or external links, but its sources remain unclear because it lacks inline citations.

Age of article

The older an article is, the more likely it has been scrutinized for verifiability, possible deletion and other factors. For example, an article that is a day old probably will have less reliable information than an article that is 2 years old. An article can be checked for its age by clicking the history tab at the top of the page, clicking "Earliest", and pressing end to see the date of the first edit.

Length of article

The lengthier an article, the more likely that there have been good contributions by many editors. However, this does not indicate high reliability if the article is young, or if there have been only a few editors.

Number of different editors

If there are many editors, this means the article has come under more scrutiny. The number of editors can be found by looking at the page history (accessed by clicking the "history" tab at the top of the page). If you see many editor names, then the article can be considered more reliable than an article with few editors. Remember that you're only initially looking at 50 edits; you can click "500" to see a longer list of edits.

Type of editors

If an article's editors are inexperienced they are more likely to be unfamiliar with Wikipedia's policies and guidelines. While they may have provided accurate information, their relatively few postings to Wikipedia may mean that they aren't committed to following Wikipedia's rules; they certainly have no reputation to protect.

Also, contributions by IP addresses (a series of numbers instead of a name, sometimes referred to as "anonymous IP editors"), are more likely to be incorrect (about a quarter of such edits are immediately reversed by other editors for one reason or another); among other reasons, there is even less accountability if someone edits without logging in. Good information can be provided by anonymous IP editors, but any information should be considered less reliable unless a source is provided.

Unfortunately, there is no easy way to see what any given information in an article was added by what editor. Nor is it easy to assess the experience of registered editors. An experimental tool called the Wikipedia trust colouring demo has been introduced to see the reliability of certain areas in an article. Unfortunately, the pages it has rated are not current.

Controversiality

Controversial subjects are prone to edit wars, bias, and generally rash edits. As a result, the information in controversial subjects may often be less reliable.

For example, articles such as Bible, Intelligent Design and An Inconvenient Truth are controversial topics which may experience issues.

However controversial subjects may be highly reliable because they may be scrutinized by valued editors simply because of their nature.

Vandalism prone

The following types of articles may be vandalism prone and therefore less reliable:

• Commonly visited articles
• Articles of an explicit nature
• Articles likely to be edited solely for vandalism, such as Gay and Penis
• Articles about common subjects learned in school, such as George Washington

Systematic Bias

The average Wikipedian on English Wikipedia is (1) a man, (2) technically inclined, (3) formally educated, (4) an English speaker (native or non-native), (5) white, (6) aged 15–49, (7) from a nominally Christian country, (8) from an industrialized nation, (9) from the Northern Hemisphere, and (10) likely employed as an intellectual rather than as a labourer (cf. Wikipedia:User survey and Wikipedia:University of Würzburg survey, 2005). As a result, it is natural for systematic bias to form.

Certain articles will be more susceptible to systematic bias. For example, the article Uses of torture in recent times tends to display information about few, but well documented, Western World cases. It neglects to document torture cases in many other countries around the world.