Wikipedia:Party and person

Different content policies and guidelines use slightly different standards. One of the commonly misunderstood distinctions is between "secondary source" and "third party".

What is a primary or secondary source?

A primary source is an original document. A secondary source is one that is based on original documents. A tertiary source is one that is based on non-original documents.

What constitutes an "original document" depends on the context. As a rule of thumb, if the document is dramatically closer to the event than you are, then it should be treated as a primary source. For example, any ancient manuscript will be considered an "original document" by modern scholars. Wikipedia often treats century-old newspaper reports as primary sources.

Person	Simple example
Primary source	An account of an event, written by an eyewitness. The first report of a scientific experiment. Court filings, legal documents, and patents. Speeches given by politicians or activists.
Secondary source	A magazine article based on previous media reports. A book about a historical event, based on letters and diaries written at the time. A scientific report that combines the results of many prior experiments into a systematic review, meta-analysis, or literature review.
Tertiary source	A modern encyclopedia or dictionary. A book about a historical event, based entirely on other people's books about the event. Most history and science textbooks intended for children.

What is a third-party source?

A third-party source is a source that isn't involved in the event. The third party is the neutral, outside observer. Classically, a third party is the judge in a lawsuit: the principal actors are the person who filed the lawsuit (the first party) and the person who is being sued (the second party). Since then, the term has expanded.

First party	Third party
The person filing the lawsuit.	The judge assigned to hear the lawsuit.
An eyewitness account of an event, by a person participating in the event.	An eyewitness account of an event, by a bystander who was not participating in the event.
The inventor of a new device.	A journalist reporting on the new device.
A press release from a political campaign.	A journalist reporting on the campaign.
The website for a company.	A journalist writing about the company.

Combinatorics

Here's how this combines:

	First party	Third party
Primary source	Scientist publishes original report about his experiments	Bystanders at a house fire write about what they saw
Secondary source	Scientist combines data from a dozen previously published experiments into a meta-analysis	Author uses bystanders' reports to write a book about house fires

Doesn't "third party" mean "independent"?

Although third-party sources are often also independent (that is, without a conflict of interest), it is not always the case. Imagine that two large companies are involved in a lawsuit. An investor who is not part of the dispute may still have a conflict of interest, because of plans to profit from the stock market's response to the lawsuit. This investor is a third party, but is not financially independent. He (or she) may have a vested interest in the dispute being seen in a particular light, or being prolonged, even though the investor is not directly involved in the lawsuit.

Footnotes