Wikipedia:Identifying and using primary sources

Identifying and using primary sources requires careful thought and some extra knowledge on the part of Wikipedia's ors.

In determining the type of source, there are three separate, basic characteristics to identify:

Every possible combination of these three traits has been seen in sources on Wikipedia. Any combination of these three traits can produce a source that is usable for some purpose in a Wikipedia article. Identifying these characteristics will help you determine how you can use these sources.

This page deals primarily with the last question: Identifying and correctly using primary sources.

Background information[]

The concept of primary, secondary, and tertiary sources originated with the academic discipline of historiography. The point was to give historians a handy way to indicate how close the source of a piece of information was to the actual events.[a]

Importantly, the concept developed to deal with "events", rather than ideas or abstract concepts. A primary source was a source that was created at about the same time as the event, regardless of the source's contents. So while a dictionary is an example of a tertiary source, an ancient dictionary is actually a primary source—for the meanings of words in the ancient world.

There are no quaternary sources: Either the source is primary, or it describes, comments on, or analyzes primary sources (in which case, it is secondary), or it relies heavily or entirely on secondary or tertiary sources (in which case, it is tertiary). The first published source for any given fact is always considered a primary source.

The historians' concept has been extended into other fields, with partial success.

Wikipedia, like many institutions, has its own lexicon. Wikipedia does not use these terms exactly like academics use them. There are at least two ways in which the term secondary source is used on Wikipedia. This page deals primarily with the classification of reliable sources in terms of article content. The classification used specifically for notability is addressed in a separate section at the end.

How to classify a source[]

A travel diary, like this handwritten manuscript from 1798, is a primary source.

Imagine that an army conquered a small country 200 years ago, and as a Wikipedia or you have the following sources:

Both the proclamation and the diary are primary sources. These primary sources have advantages: they were written at the time, and so are free of the opinions and fictions imposed by later generations. They also have disadvantages: the proclamation might contain propaganda designed to pacify the conquered country, or omit politically inconvenient facts, or overstate the importance of other facts, or be designed to stroke the new ruler's ego. The diary will reflect the prejudices of its author, and its author might be unaware of relevant facts.

The book and the journal article are secondary sources. These secondary sources have advantages: The authors were not involved in the event, so they have the emotional distance that allows them to analyze the events dispassionately. They also have disadvantages: In some topic areas the authors are writing about what other people said happened and cannot use their own experience to correct any errors or omissions. The authors may be unable to see clearly through their own cultural lens, and the result may be that they unconsciously emphasize things important to their cultures and times, while overlooking things important to the actual actors.

The encyclopedia article is a tertiary source. It has advantages: it summarizes information. It also has disadvantages: in relying on the secondary source, the encyclopedia article will repeat, and may accidentally amplify, any distortions or errors in that source. It may also add its own interpretation.

This sort of simple example is what the source classification system was intended to deal with. It has, however, been stretched to cover much more complicated situations.

Uses in fields other than history[]

Summary page of a scientific paper documenting an experiment in treating bulimia nervosa with electrical stimulation of the brain
The initial publication of data from a scientific experiment, such as a clinical trial, is a primary source.

In science, data is primary, and the first publication of any idea or experimental result is always a primary source. These publications, which may be in peer-reviewed journal articles or in some other form, are often called the primary literature to differentiate them from unpublished sources. Narrative reviews, systematic reviews and meta-analyses are considered secondary sources, because they are based on and analyze or interpret (rather than merely citing or describing) these original experimental reports.

In the fine arts, a work of art is always a primary source. This means that novels, plays, paintings, sculptures, and such are always primary sources. Statements made by or works written by the artists about their artwork might be primary or secondary. Critiques and reviews by art critics are usually considered secondary sources, although exceptions exist. For example, an account of the specific circumstances under which the critic viewed the artwork is primary material, as is the critics' description of their personal emotional reaction to the piece. As a result, some critiques and reviews are a mix of primary and secondary material.

Among genealogists, a primary source comes from a direct witness, a secondary source comes from second-hand information or hearsay told to others by witnesses, and tertiary sources can represent either a further link in the chain or an analysis, summary, or distillation of primary and/or secondary sources. In this system, an elderly woman's description of her wedding day from many decades before is a primary source; her granddaughter's plain repetition of that information to her schoolteacher is considered secondary by genealogists, and if the schoolteacher goes home that evening and writes down what the granddaughter said, then the schoolteacher is producing a tertiary source. In other systems, all of these sources are primary. Genealogists also differentiate between original documents, accurate copies (photographs, photocopies or unaltered digital scans) of the original documents, and derivatives (handwritten or re-typed transcripts, digitally enhanced copies, or other methods of copying that might introduce changes or errors). Copies and derivatives retain the same status as the original in the primary-secondary-tertiary classification, unless the derivative is so different as to represent a transformative summary, in which case it becomes a tertiary source.

In some disciplines, notably law, the concept of tertiary sources is not used. In this two-part system, what would typically be classified as a tertiary source by other disciplines is lumped in with secondary sources.

Not a matter of counting the number of links in the chain[]

Consider the simple example above: the original proclamation is a primary source. Is the book necessarily a secondary source?

The answer is: not always. If the book merely quotes the proclamation (such as re-printing a section in a sidebar or the full text in an appendix, or showing an image of the signature or the official seal on the proclamation) with no analysis or commentary, then the book is just a newly printed copy of the primary source, rather than being a secondary source. The text and images of the proclamation always remain primary sources.

It's not a matter of counting up the number of sources in a chain. The first published source is always a primary source, but it is possible to have dozens of sources, without having any secondary or tertiary sources. If Alice writes down an idea, and Bob simply quotes her work, and Chris refers to Bob's quotation, and Daisy cites Chris, and so forth, you very likely have a string of primary sources, rather than one primary, one secondary, one tertiary, and all subsequent sources with made-up classification names.

Characteristics of a secondary source[]

All sources are primary for something[]

Every source is the primary source for something, whether it be the name of the author, its title, its date of publication, and so forth. For example, no matter what kind of book it is, the copyright page inside the front of a book is a primary source for the date of the book's publication. Even if the book would normally be considered a secondary source, if the statement that you are using this source to support is the date of its own publication, then you are using that book as a primary source.

More importantly, many high-quality sources contain both primary and secondary material. A textbook might include commentary on the proclamation (which is secondary material) as well as the full text of the proclamation (which is primary material). A peer-reviewed journal article may begin by summarizing a careful selection of previously published works to place the new work in context (which is secondary material) before proceeding into a description of a novel idea (which is primary material). An author might write a book about an event that is mostly a synthesis of primary-source news stories (which is secondary material), but they might add occasional information about personal experiences or new material from recent interviews (which is primary material). The book about love letters might analyze the letters (which is secondary material) and provide a transcription of the letters in an appendix (which is primary material). The work based on previously published sources is probably a secondary source; the new information is a primary source.

How you use the source affects the classification of the source.

"Secondary" does not mean "good"[]

"Secondary" is not, and should not be, a bit of jargon used by Wikipedians to mean "good" or "reliable" or "usable". Secondary does not mean that the source is independent, authoritative, high-quality, accurate, fact-checked, expert-approved, subject to orial control, or published by a reputable publisher. Secondary sources can be unreliable, biased, self-serving and self-published.

According to our content guideline on identifying reliable sources, reliable sources have most, if not all, of the following characteristics:

A primary source can have all of these qualities, and a secondary source may have none of them. Deciding whether primary, secondary or tertiary sources are appropriate on any given occasion is a matter of good orial judgment and common sense, not merely mindless, knee-jerk reactions to classification of a source as "primary" or "secondary".

"Primary" does not mean "bad"[]

"Primary" is not, and should not be, a bit of jargon used by Wikipedians to mean "bad" or "unreliable" or "unusable". While some primary sources are not fully independent, they can be authoritative, high-quality, accurate, fact-checked, expert-approved, subject to orial control, and published by a reputable publisher.

Primary sources can be reliable, and they can be used. Sometimes, a primary source is even the best possible source, such as when you are supporting a direct quotation. In such cases, the original document is the best source because the original document will be free of any errors or misquotations introduced by subsequent sources.

However, there are limitations in what primary sources can be used for.

Primary sources should be used carefully[]

Material based on primary sources can be valuable and appropriate additions to articles. However, primary sources may only be used on Wikipedia to make straightforward, descriptive statements that any educated person—with access to the source but without specialist knowledge—will be able to verify are directly supported by the source. This person does not have to be able to determine that the material in the article or in the primary source is true. The goal is only that the person could compare the primary source with the material in the Wikipedia article, and agree that the primary source actually, directly says just what the article says it does.

^ A person's or an organization's website could contain some secondary material about itself, although this is not very common. Such material would still be self-published as well as first-party/affiliated/non-independent material, and thus would still be subject to restrictions in how you can use it.

Secondary sources for notability[]

Just because topics are covered in primary sources does not mean that they are notable. Information about an author from the book jacket copy of the author's own book does not demonstrate notability, for example. Secondary sources are needed to establish notability for the purposes of deciding which articles to keep. However topics that are only covered briefly or in poor quality secondary sources may not meet the general notability guideline.

AFDs (articles for deletion) require showing that topics meet the general notability guideline's requirement that secondary sources exist. It is difficult, if not impossible, to find secondary sources for run-of-the-mill events and breaking news. Once a couple of years have passed, if no true secondary sources can be found, the article is usually deleted.

Are news-reporting media secondary or primary sources?[]

The term "news-reporting media" is used here in the sense of actual newspapers and other media reporting news in a manner similar to newspapers.

Wikipedia fairly often writes about current events. As a result, an event may happen on Monday afternoon, may be written about in Tuesday morning's newspapers, and may be added to Wikipedia just minutes later. Many ors—especially those with no training in historiography—call these newspaper articles "secondary sources". Most reliable sources in academia, however, name typical contemporary newspaper stories as primary sources.

Several academic research guides name newspaper articles written at the same time as the event as one kind of primary source.[b] Yale University's guide to comparative literature lists newspaper articles as both primary and secondary sources, depending on whether they contain an interpretation of primary source material.[2] Other university libraries address newspaper sources in more detail, for instance:

Similar definitions of primary sources are cited by the policy on original research. While most news stories are considered primary sources, some can be secondary sources, as explained below.

Examples of news reports as primary sources[]

Eyewitness news
The television news presenter stands in front of a burning house and describes the fire. The newspaper journalist describes the scene of a major car wreck that their or sent them to.
Breaking news
The wire service announces that a prominent politician has been taken to the hospital. The weather service says that a tornado has touched down.
Reports on events
The newspaper journalist describes the discussions from a meeting of the local school agency. The radio announcer reports the arrest of an alleged criminal.
Human interest stories
The magazine publishes a touching story about a child with a congenital heart defect. The society column in the newspaper reports the birthday of a prominent local citizen.
Interviews and reports of interviews
The reporter quotes the politician's speech. The talk show host interviews a celebrity. (Defined as a primary source by policy.)
Investigative reports
The journalist goes undercover and reports their experiences. The journalist meets with people and reads documents to uncover corruption. (Defined as a primary source by policy.)
Editorials, opinions, and op-eds
The newspaper orial staff announces its support for a proposed law. The syndicated columnist explains their idea for fixing the economy. (Defined as a primary source by policy.)

Examples of news reports as secondary sources[]

Historical reports
A special television program is broadcast to mark the 60th anniversary of the end of World War II. A newspaper column lists the events reported in that newspaper on the same date from 25, 50, 75, and 100 years before and comments on their relevance to modern times.
Analytical reports
The newspaper publishes a week-long series of articles on health care systems in the nation. This is not merely a piece that provides one or two comments from someone who is labeled an "analyst" in the source, but is a major work that collects, compares, and analyzes information.
Book reviews
Book reviews are generally secondary sources if they provide information beyond a basic description of the book's contents. Book reviews are often a mix of primary and secondary material: e.g., an analysis of some aspect of the book (secondary) plus the reviewer's rating or opinion about the book (primary). Simple plot summaries, synopses, other basic descriptions of a work's contents are generally primary sources.

Again, "Primary" is not another way to spell "bad". Just because most newspaper articles are primary sources does not mean that these articles are not reliable and often highly desirable independent sources.

See also[]


  1. ^ According to Yale University: "Primary sources provide firsthand testimony or direct evidence concerning a topic or question under investigation. They are usually created by witnesses or recorders who experienced the events or conditions being documented. Often these sources are created at the time when the events or conditions are occurring, but primary sources can also include autobiographies, memoirs, and oral histories recorded later".[1]
  2. ^ See for example:
    • Knowlton, Steven. "Primary sources: A guide for historians: Introduction". Princeton University Library.
    • Lee, Corliss. "Finding Historical Primary Sources: Getting Started". UC Berkeley Libraries.
    • Bell, Emily. "Library Research Guide: History of Science: Introduction: What is a Primary Source?". Harvard University Library.


  1. ^ "Primary Sources at Yale". Yale University.
  2. ^ Gilman, Todd. "Comparative Literature: Primary, Secondary & Tertiary Sources". Yale University Library. Archived from the original on February 6, 2017. Retrieved February 10, 2017.
  3. ^ "Primary, secondary and tertiary sources: Secondary". Queensland, Australia: James Cook University. Retrieved October 22, 2020.
  4. ^ "Primary and Secondary Sources". Ithaca College Library. Archived from the original on June 18, 2017. Retrieved June 15, 2017.
  5. ^ González, Luis A. (2014). "Identifying Primary and Secondary Sources". Indiana University Libraries. Retrieved March 18, 2021.{{cite web}}: CS1 maint: url-status (link)
  6. ^ Sanford, Emily (2010). "Primary and Secondary Sources: An Overview". Bentley Historical Library, University of Michigan. Archived from the original on 22 September 2011.