What Are Credible Sources? | Definition & Examples
Credible sources are unbiased and evidence-based materials that have reliable authors. Credible sources are key to strong academic writing.
Given the abundance of sources you can encounter, knowing how to differentiate between what is credible and what isn’t is a fundamental information literacy skill. Using credible sources means that your arguments are based on accurate, reliable information.
Types of sources
Sources can be divided into three categories: primary sources, secondary sources, and tertiary sources.
Primary sources are generally viewed as the most credible source type because they provide firsthand evidence of the research subject. Nevertheless, you should still check primary sources for reliability and accuracy.
All three source types are useful at different stages of the research process.
| Type | Definition | Example |
|---|---|---|
| Primary | Direct evidence of the research subject, original data |
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| Secondary | Analyses, interpretations, or commentaries regarding primary sources |
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| Tertiary | Collections of information that index or summarize primary and secondary sources |
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How to identify a credible source
Identifying credible sources is a key skill for academic writing. Evaluating the credibility of a source involves several criteria:
- The information should be current and up-to-date.
- The information should be related to your research subject.
- The author and publisher should be established and reputable.
- The information should be unbiased, accurate, and verifiable.
- Online sources should have a trustworthy URL and layout.
The CRAAP test
The CRAAP test is a tool for evaluating a source’s credibility. It was developed in 2004 by librarians from California State University.
The CRAAP test comprises five components:
- Currency: Is the source current?
- Relevance: Is the source pertinent to your topic?
- Authority: Does the source come from a reliable publisher and author?
- Accuracy: Is the information correct? Is there evidence supporting the information?
- Purpose: Why was this source published?
Your research topic determines the criteria for how you will evaluate each component.
For example, if you are researching the conditions in London’s slums at the time Charles Dickens was writing, the currency of the sources you use is less important than if you are researching trends in consumer behavior in the Digital Age.
Purpose is a particularly difficult component to evaluate as materials may have various motivations behind them. For example, a research paper evaluating the impact of processed ingredients in the diet may appear credible, but if the research received funding from food manufacturers, it may be biased.
Generally, if a source is attempting to convince you to buy something, it shouldn’t be considered credible.
Newspapers can serve as excellent primary sources for information on a historical event, but not all news sources are reliable and accurate, particularly when it comes to online news. Authority is a key component to consider when using news as a source.
When using books, check that they are from a reputable publisher. For academic journal articles, confirm that they have been peer reviewed.
What is peer review?
Peer review is a process for evaluating the quality of an academic text submitted for publication in an academic journal. Peer review panels are composed of various experts in a given field, and they determine whether the submission is of sufficient quality to be published according to set criteria.
The peer review process means that academic journals are generally credible sources for research projects.
Finding credible sources
The types of sources you’ll use depend on your research subject.
In the initial research process stages, tertiary sources are a great starting point, and primary and secondary sources can also come in handy.
- Databases
- Websites with .edu or .org URLs
- Encyclopedias
- Textbooks
- Research-oriented magazines like Nature Weekly or ScienceMag
Further along in the research process, academic journals and scholarly books can help you to deepen your knowledge.
Academic journals are generally highly credible sources and publish up-to-date, well-supported research.
- Can you access the journal’s peer review and copyright policies?
- Does the author have a strong publication history? You can check using Google Scholar.
- Does the author have many citations by other researchers? A high number of “Cited By” results on Google Scholar indicates credibility.
- Is the journal indexed in academic databases?
- Does the journal have an “About” and “Scope” page establishing the type of content they publish?
- Has the journal had to retract many articles?
Google Scholar is an excellent resource for finding academic or scholarly sources, particularly at the start of your research process. Other academic databases you might consult include LexisNexis and government open data.
Open Educational Resources (OERs) are “free use” materials available in educational settings. To use these materials, check for a Creative Commons license to ensure that they can be shared. It is also important to vet these materials using the CRAAP test criteria, particularly regarding authority.
OER Commons, curated by librarians, is a public digital library that is a great jumping-off point.
| Interdisciplinary | |
| Social Science + Humanities | |
| Science + Mathematics |
Evaluating web sources
Online sources are especially tricky to evaluate for credibility. These sources may not have specified authors or publication dates, and you may need to do some digging to determine their motivation.
Moreover, unlike academic journals and books, websites do not have to undergo rigorous peer-review and editing processes.
Have a look at the URL to verify a website’s credibility. Different domains can give you insight into what type of organization has published the content.
| Affiliation | Domain extension |
|---|---|
| Commercial or profit-driven | .com (or other country-specific domains, e.g., .ca) |
| Advocacy or non-profit organizations | .org |
| Government-affiliated websites | .gov |
| Educational resources (considered the most credible for academic writing) | .edu |
Content that contains a lot of “clickbait,” buzzwords, emotional or subjective language, and vagueness likely isn’t credible. Be sure to evaluate any information that isn’t cited or supported by evidence as well as sweeping claims.
Questions you might ask while evaluating a website include:
- Does the site have a professional look? Is the layout neat and organized?
- Can you find an “About” page detailing the site’s purpose and the type of content it publishes?
- Is there a way to contact the organization or author to request more information about something they have published?
- Does it link to other trustworthy sources?
- Is the information verifiable?
- How recently was the website updated? Infrequent updates may indicate a lack of credibility.
- Is the website full of advertising and sponsored content? This may indicate bias and therefore a lack of credibility.
- Does the website receive funding from another organization? Funding may indicate ulterior motives behind the information published.
Using social media or personal blogs or websites can help you start brainstorming ideas, but these sources are often subjective and shouldn’t generally be used in your final research paper.
On the same note, while it can be a useful first step for becoming acquainted with a topic, Wikipedia is open to editing by anyone at any time and therefore does not constitute a credible source.
Frequently asked questions about credible sources
- What makes a source credible?
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Sources can be vetted using the CRAAP test as well as checked for the following points to ensure credibility:
- Updated information
- Trustworthy publisher and author with relevant credentials for the topic
- Cited materials should be able to be consulted and unbiased
- Online sources should have a trustworthy URL and layout
Quillbot’s Citation Generator tool can help you to create and manage your citations throughout the research process.
- Is Wikipedia a credible source?
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Wikipedia is not generally considered a credible source on its own. This is because Wikipedia is an open-access platform that anyone can edit at any time. Thus, while Wikipedia can be helpful when just starting out in your research, it should not be cited among your sources in your final paper.
However, you can use the references cited in Wikipedia articles to access the research materials the articles are based on. If a Wikipedia article cites academic sources such as journal articles, go directly to these sources to perform more in-depth research. These sources can be used to support your paper.
- How can you tell if a source is primary or secondary?
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To evaluate whether a source is a primary or secondary source, ask the following questions:
- Is the source from someone who participated in the studied event (primary) or from another researcher (secondary)?
- Am I examining the source itself (primary) as my main research objective, or is it supplying background information?
- Does the source give novel information or data (primary), or is it commenting on, interpreting, and or analyzing information from other sources (secondary)?
Some sources generally always serve as primary sources. These include artworks and literature, raw statistics, official documents and records, and personal communications such as journal entries or interviews.
Primary sources are generally considered the most credible evidence to use to support an argument because they are directly involved with the research subject. However, you should still vet these sources for reliability and accuracy.
All sources you use must be accompanied by a citation to avoid plagiarism. You can use QuillBot’s Citation Generator to automatically generate citations for all types of sources.
