When researching your topic, which sources of information should you avoid? check all that apply.

In general, you must document sources when you provide information that you ordinarily would not have known before conducting your research, and when you provide information that it cannot be assumed the reader knows. You must cite a reference when you:

  • Discuss, summarize, or paraphrase the ideas of an author
  • Provide a direct quotation
  • Use statistical or other data
  • Use images, graphics, videos, and other media

While you are doing research and locating sources, be sure to document materials thoroughly, noting the author, title, publisher, place of publication, date, and page numbers of all sources used. For electronic materials, you should also note the DOI number (Digital Object Identifier) if available. Note the URL of any website you consult; depending on the source, you may need it for the reference.

APA style no longer requires a database name for most references; MLA style still requires it as part of your citation. In either case, make a note of it in case you need to retrieve it at a later date.

Common Knowledge

Things that are common knowledge do not require citation. For example:

  • Social networking sites such as Facebook allow people to communicate easily regardless of their location. (does not require citation)
  • The Japanese navy attacked Pearl Harbor on December 7, 1941. (does not require citation)

However, if someone draws an original conclusion from a common fact, then you must cite the source:

  • The ability to share real-time news and video with the world via social networking sites has emboldened student movements in countries where there is very little freedom of the press. (requires citation)
  • Japan's failure to sink any U.S. aircraft carriers in the otherwise devastating attack on Pearl Harbor assured Japan's eventual defeat. (requires citation)

Also, common sayings or proverbs need not be cited:

  • "The early bird gets the worm." (common expression with no distinct origin)

Below is a famous saying you might recognize, but it's actually from a poem by Sir Walter Scott. If you read this in a book, of course, you would cite the book. If you already knew this expression, you should still give Sir Walter Scott credit for it because it has a distinct and identifiable origin.

  • "Oh, what a tangled web we weave when first we practice to deceive."

What about Google Search Results?

Search engines such as Google use algorithms to filter, or tailor, the search results you see. Based on previous searches you have done - the sites you have viewed, what you clicked on and other data that can be gathered from your browser - Google will give you search results tailored for you using a 'relevance algorithm'. That is why you will often notice advertisements or recommendations for products and services based on where you shop and what you watch online. 

So the exact same search, using exactly the same search words, can return different results for different individuals. Are you comfortable with the idea that a computer is making decisions about what information you are shown in your search results?

Eli Pariser is the author of the book The Filter Bubble and he gave a TED talk based on that book. Click on the video to view this fascinating TED talk and learn more about how filter bubbles may impact how you search for information online.

A credible source is free from bias and backed up with evidence. It is written by a trustworthy author or organization.

There are a lot of sources out there, and it can be hard to tell what’s credible and what isn’t at first glance.

Evaluating source credibility is an important information literacy skill. It ensures that you collect accurate information to back up the arguments you make and the conclusions you draw.

Types of sources

There are many different types of sources, which can be divided into three categories: primary, secondary, and tertiary.

Primary sources are often considered the most credible in terms of providing evidence for your argument, as they give you direct evidence of what you are researching. However, it’s up to you to ensure the information they provide is reliable and accurate.

You will likely use a combination of the three types over the course of your research process.

Type Definition Example
Primary First-hand evidence giving you direct access to your research topic
  • Empirical or statistical results
  • Newspapers and magazines
  • Letters or diary entries
  • Photographs
  • Audio clips, such as speeches or interviews
Secondary Second-hand information that analyzes, describes, or evaluates primary sources
  • Books
  • Journal articles
  • Blog posts
  • Textbooks
  • Documentaries
Tertiary Sources that identify, index, or consolidate primary and secondary sources
  • Encyclopedias
  • Dictionaries
  • Almanacs
  • Bibliographies
  • Indexes

How to identify a credible source

There are a few criteria to look at right away when assessing a source. Together, these criteria form what is known as the CRAAP test.

  • The information should be up-to-date and current.
  • The source should be relevant to your research.
  • The author and publication should be a trusted authority on the subject you are researching.
  • The sources the author cited should be easy to find, clear, and unbiased.
  • For web sources, the URL and layout should signify that it is trustworthy.

The CRAAP test

The CRAAP test is a catchy acronym that will help you evaluate the credibility of a source you are thinking about using. California State University developed it in 2004 to help students remember best practices for evaluating content.

The 5 components of the CRAAP test
  • Currency: Is the source up-to-date?
  • Relevance: Is the source relevant to your research?
  • Authority: Where is the source published? Who is the author? Are they considered reputable and trustworthy in their field?
  • Accuracy: Is the source supported by evidence? Are the claims cited correctly?
  • Purpose: What was the motive behind publishing this source?

The criteria for evaluating each point depend on your research topic.

For example, if you are researching cutting-edge scientific technology, a source from 10 years ago will not be sufficiently current. However, if you are researching the Peloponnesian War, a source from 200 years ago would be reasonable to refer to.

Be careful when ascertaining purpose. It can be very unclear (often by design!) what a source’s motive is. For example, a journal article discussing the efficacy of a particular medication may seem credible, but if the publisher is the manufacturer of the medication, you can’t be sure that it is free from bias. As a rule of thumb, if a source is even passively trying to convince you to purchase something, it may not be credible.

TipTake a look at what sources the author cited. Are they trustworthy? As a bonus, investigating the sources used may help you find new sources to add to your own bibliography.

Newspapers can be a great way to glean first-hand information about a historical event or situate your research topic within a broader context. However, the veracity and reliability of online news sources can vary enormously—be sure to pay careful attention to authority here.

When evaluating academic journals or books published by university presses, it’s always a good rule of thumb to ensure they are peer-reviewed and published in a reputable journal.

What is peer review?

The peer review process evaluates submissions to academic journals. A panel of reviewers in the same subject area decide whether a submission should be accepted for publication based on a set of criteria.

For this reason, academic journals are often considered among the most credible sources you can use in a research project– provided that the journal itself is trustworthy and well-regarded.

Where to find credible sources

What sources you use depend on the kind of research you are conducting.

For preliminary research and getting to know a new topic, you could use a combination of primary, secondary, and tertiary sources.

Credible sources for preliminary researchDepending on your topic, consider starting with:
  • Encyclopedias
  • Textbooks
  • Websites with .edu or .org domains
  • News sources with first-hand reporting
  • Research-oriented magazines like ScienceMag or Nature Weekly.

As you dig deeper into your scholarly research, books and academic journals are usually your best bet.

Academic journals are often a great place to find trustworthy and credible content, and are considered one of the most reliable sources you can use in academic writing.

Assessing journal credibility
  • Is the journal indexed in academic databases?
  • Has the journal had to retract many articles?
  • Are the journal’s policies on copyright and peer review easily available?
  • Are there solid “About” and “Scope” pages detailing what sorts of articles they publish?
  • Has the author of the article published other articles? A quick Google Scholar search will show you.
  • Has the author been cited by other scholars? Google Scholar also has a function called “Cited By” that can show you where the author has been cited. A high number of “Cited By” results can often be a measurement of credibility.

Google Scholar is a search engine for academic sources. This is a great place to kick off your research. You can also consider using an academic database like LexisNexis or government open data to get started.

Open Educational Resources, or OERs, are materials that have been licensed for “free use” in educational settings. Legitimate OERs can be a great resource. Be sure they have a Creative Commons license allowing them to be duplicated and shared, and meet the CRAAP test criteria, especially in the authority section. The OER Commons is a public digital library that is curated by librarians, and a solid place to start.

TipIf you find that a journal article you’re interested in referring to is behind a paywall, check to see if your academic institution has a membership. Many university library systems have accounts with major journals.

Evaluating web sources

It can be especially challenging to verify the credibility of online sources. They often do not have single authors or publication dates, and their motivation can be more difficult to ascertain.

Websites are not subject to the peer-review and editing process that academic journals or books go through, and can be published by anyone at any time.

When evaluating the credibility of a website, look first at the URL. The domain extension can help you understand what type of website you’re dealing with.

Website domain extensions
  • Educational resources end in .edu, and are generally considered the most credible in academic settings.
  • Advocacy or non-profit organizations end in .org.
  • Government-affiliated websites end in .gov.
  • Websites with some sort of commercial aspect end in .com (or .co.uk, or another country-specific domain).

In general, check for vague terms, buzzwords, or writing that is too emotive or subjective. Beware of grandiose claims, and critically analyze anything not cited or backed up by evidence.

Some questions to ask yourself could include:
  • How does the website look and feel? Does it look professional to you?
  • Is there an “About Us” page, or a way to contact the author or organization if you need clarification on a claim they have made?
  • Are there links to other sources on the page, and are they trustworthy?
  • Can the information you found be verified elsewhere, even via a simple Google search?
  • When was the website last updated? If it hasn’t been updated recently, it may not pass the CRAAP test.
  • Does the website have a lot of advertisements or sponsored content? This could be a sign of bias.
  • Is a source of funding disclosed? This could also give you insight into the author and publisher’s motivations.

Social media posts, blogs, and personal websites can be good resources for a situational analysis or grounding of your preliminary ideas, but exercise caution here. These highly personal and subjective sources are seldom reliable enough to stand on their own in your final research product.

Similarly, Wikipedia is not considered a reliable source due to the fact that it can be edited by anyone at any time. However, it can be a good starting point for general information and finding other sources.

TipScroll all the way down to the bottom of the Wikipedia article. Here, you will see a footnotes section for references and further reading. There are often credible sources linked here, such as scholarly articles or books, that can aid your research.

Frequently asked questions

What makes a source credible?

A credible source should pass the CRAAP test and follow these guidelines:

  • The information should be up to date and current.
  • The author and publication should be a trusted authority on the subject you are researching.
  • The sources the author cited should be easy to find, clear, and unbiased.
  • For a web source, the URL and layout should signify that it is trustworthy.

What is the definition of peer review?

Peer review is a process of evaluating submissions to an academic journal. Utilizing rigorous criteria, a panel of reviewers in the same subject area decide whether to accept each submission for publication. For this reason, academic journals are often considered among the most credible sources you can use in a research project– provided that the journal itself is trustworthy and well-regarded.

What is the CRAAP test?

The CRAAP test is an acronym to help you evaluate the credibility of a source you are considering using. It is an important component of information literacy.

The CRAAP test has five main components:

  • Currency: Is the source up to date?
  • Relevance: Is the source relevant to your research?
  • Authority: Where is the source published? Who is the author? Are they considered reputable and trustworthy in their field?
  • Accuracy: Is the source supported by evidence? Are the claims cited correctly?
  • Purpose: What was the motive behind publishing this source?

What are examples of academic dishonesty?

Academic dishonesty can be intentional or unintentional, ranging from something as simple as claiming to have read something you didn’t to copying your neighbor’s answers on an exam.

You can commit academic dishonesty with the best of intentions, such as helping a friend cheat on a paper. Severe academic dishonesty can include buying a pre-written essay or the answers to a multiple-choice test, or falsifying a medical emergency to avoid taking a final exam.