Wikipedia:Identifying and using primary and secondary sources
|While this essay is not a Wikipedia policy or guideline itself, it is intended to supplement the Wikipedia:No original research's Primary, secondary and tertiary sources subsection, to which editors should defer in case of inconsistency between that page and this one.|
Identifying and using primary and secondary sources requires careful thought and some extra knowledge on the part of Wikipedia's editors.
In determining the type of source, there are three separate, basic characteristics to identify:
- Is this source self-published or not? (If so, then see Wikipedia:Identifying and using self-published sources.)
- Is this source independent or third-party, or is it closely affiliated with the subject?
- Is this source primary or not?
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 and non-primary sources.
- 1 Source classification in the real world
- 2 Wikipedia is not the real world
- 3 How to classify a source
- 4 "Secondary" is not another way to spell "good"
- 5 You are allowed to use primary sources... carefully
- 6 Secondary sources for notability
- 7 Are news-reporting media secondary or primary sources?
- 8 Notes
Source classification in the real world
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.
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 is not the real world
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
Imagine that an army conquered a small country 200 years ago, and you have the following sources:
- a proclamation of victory written at the time of the conquest,
- a diary written by someone who lived at the time and talks about it,
- a book written 150 years later, that analyzes the proclamation,
- an academic journal article written two years ago that examines the diary, and
- an encyclopedia entry written last year, based on both the book and the journal.
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
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 his or her 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) 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.
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
- A secondary source is built from primary sources. Secondary sources are not required to provide you with a bibliography, but you should have some reason to believe that the source is building on the foundation of prior sources rather than starting with all-new material. For example, century-old love letters on display at a museum are primary sources; a secondary source might analyze the contents of these letters. The fact that the analysis is based on these letters would be evident from the description in the source, even if the paper contained no footnotes.
- A secondary source is significantly separated from these primary sources. A reporter's notebook is an (unpublished) primary source, and the news story published by the reporter based on those notes is also a primary source. This is because the sole purpose of the notes in the notebook is to produce the news report. If a journalist later reads dozens of these primary-source news reports and uses those articles to write a book about a major event, then this resulting work is a secondary source. This separation is not defined by the length of time that elapses or geographical distance.
- A secondary source usually provides analysis, commentary, evaluation, context, and interpretation. It is this act of going beyond simple description, and telling us the meaning behind the simple facts, that makes them valuable to Wikipedia.
- Reputable secondary sources are usually based on more than one primary source. High-quality secondary sources often synthesize multiple primary sources, in due proportion to the expert-determined quality of the primary sources. This helps us present the material in due proportion to the sources' actual importance, rather than in due proportion to the size of the sources' publicity budgets.
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 he 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" is not another way to spell "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 editorial control, or published by a reputable publisher. Secondary sources can be unreliable, biased, self-serving and self-published.
- It has a reputation for fact-checking and accuracy.
- It is published by a reputable publishing house, rather than by the author(s).
- It is "appropriate for the material in question", i.e., the source is directly about the subject, rather than mentioning something unrelated in passing.
- It is a third-party or independent source, with no significant financial or other conflict of interest.
- It has a professional structure in place for deciding whether to publish something, such as editorial oversight or peer review processes.
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 editorial judgment and common sense, not merely mindless, knee-jerk reactions to classification of a source as "primary" or "secondary".
"Primary" is not another way to spell "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 editorial 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.
You are allowed to use primary sources... carefully
Material based on primary sources can be valuable and appropriate additions to articles.
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 we're saying it does.
- An article about the conquest of the hypothetical country above: The proclamation itself is an acceptable primary source for a simple description of the proclamation, including its size, whether it was written in blackletter calligraphy, whether it is signed or has an official seal, and what words, dates, or names were on it. Anyone should be able to look at an image of the proclamation and see that it was all written on one page, whether it used that style of calligraphy, and so forth. However, the proclamation's authenticity, meaning, relevance, importance, typicality, influences, and so forth should all be left to the book that analyzed it, not to Wikipedia's editors.
- An article about a novel: The novel itself is an acceptable primary source for information about the plot, the names of the characters, the number of chapters, or other contents in the book: Any educated person can read Jane Austen's Pride and Prejudice and discover that the main character's name is Elizabeth or that there are 61 chapters. It is not an acceptable source for claims about book's style, themes, foreshadowing, symbolic meaning, values, importance, or other matters of critical analysis, interpretation, or evaluation: No one will find a direct statement of this material in the book.
- An article about a painting: The painting itself is an acceptable primary source for information about the colors, shapes, and figures in the painting. Any educated person can look at Georgia O'Keeffe's Cow Skull: Red, White, and Blue, and see that it is a painting of a cow's skull on a background of red, white, and blue. It is not an acceptable source for claims about the artist's motivation, allusions or relationships to other works, the meaning of the figures in the painting, or any other matters of analysis, interpretation, or evaluation: Looking at the painting does not tell anyone why the artist chose these colors, whether she meant to evoke religious or patriotic sentiments, or what motivated the composition.
- An article about a person: The person's autobiography, own website, or a page about the person on an employer's or publisher's website, is an acceptable (although possibly incomplete) primary‡ source for information about what the person says about himself or herself. Such primary sources can normally be used for non-controversial facts about the person and for clearly attributed controversial statements. Many other primary sources, including birth certificates, the Social Security Death Index, and court documents, are usually not acceptable primary sources, because it is impossible for the viewer to know whether the person listed on the document is the notable subject rather than another person who happens to have the same name.
- An article about a business: The organization's own website is an acceptable (although possibly incomplete) primary‡ source for information about what the company says about itself and for most basic facts about its history, products, employees, finances, and facilities. It is not likely to be an acceptable source for most claims about how it or its products compare to similar companies and their products (e.g., "OurCo's Foo is better than Brand X"), although it will be acceptable for some simple, objective comparison claims ("OurCo is the oldest widget business in Smallville" or "OurCo sells more widgets than anyone else in New Zealand"). It is never an acceptable source for claims that evaluate or analyze the company or its actions, such as an analysis of its marketing strategies (e.g., "OurCo's sponsorship of National Breast Cancer Month is an effective tool in expanding sales to middle-aged, middle-class American women").
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 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.
One very rough rule of thumb historians use for identifying primary sources is this: if the source is more than half as old as the event, then it's a primary source. For example, if an event occurred on January 1, 1800, and a newspaper article about it was printed in 1850, then historians in the twentieth century and later consider the newspaper article a primary source.
However, 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 editors—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. The definitions cited by the relevant policy state that newspaper articles are primary sources. However, while this is generally true, there are some exceptions.
These kinds of media reports are 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 his editor sent him 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 his or her 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 editorial staff announces its support for a proposed law. The syndicated columnist explains his idea for fixing the economy. (Defined as a primary source by policy.)
These kinds of media reports are usually, or at least might be, 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.
- 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.
- Here is a sampling of university-based sources that address the question:
- "A newspaper article is a primary source if it reports events, but a secondary source if it analyses and comments on those events." 
- "Characteristically, primary sources are contemporary to the events and people described [e.g., like a newspaper article on a current event]... Examples of primary sources include...newspaper ads and stories. In writing a narrative of the political turmoil surrounding the 2000 U.S. presidential election, a researcher will likely tap newspaper reports of that time for factual information on the events. The researcher will use these reports as primary sources because they offer direct or firsthand evidence of the events, as they first took place." 
- "There can be grey areas when determining if an item is a primary source or a secondary source. For example, newspaper journalists may interview eyewitnesses but not be actual eyewitnesses themselves. They also may have completed research to inform their story. Traditionally, however, newspapers are considered primary sources…. Examples of common primary source formats can include...contemporary newspaper articles…. Newspaper articles, although often written after an event has occurred, are traditionally considered a primary source…. " 
- "Examples of primary information: A current news report that is reporting the facts (not analysis or evaluation) of an event." 
- What are primary sources? Published materials (books, magazine and journal articles, newspaper articles) written at the time about a particular event. While these are sometimes accounts by participants, in most cases they are written by journalists or other observers. The important thing is to distinguish between material written at the time of an event as a kind of report, and material written much later, as historical analysis."