Skip to Main Content

Research Skills for Students

An Open Educational Resource


Thinking Critically About Sources

This section teaches how to identify relevant and credible sources that you have most likely turned up on the Web and on your results pages of the library catalog, Google Scholar, and specialized databases. Relevant, credible sources will meet the information needs of your of your research project.


In order to evaluate a source, you have to answer two questions about it:

  • Is this source relevant to my research question?
  • Is this a credible source– a source my audience and I should be able to believe?

You will probably find it helpful to determine relevance before credibility because no matter how credible a source is, if it's not relevant to your research question it's useful to you for the project you are working on!

Making Inferences: Good Enough for Your Purpose?

Sources should always be evaluated relative to your purpose – why you’re looking for information. But because there often aren’t clear-cut answers when you evaluate sources, most of the time it is inferences – educated guesses from available clues – that you have to make about whether to use information from particular sources.

Your information needs will dictate:

  • What kind of information will help.
  • How serious you consider the consequences of making a mistake by using information that turns out to be inaccurate. When the consequences aren’t very serious, it’s easier to decide a source and its information are good enough for your purpose. Of course, there’s a lot to be said for always having accurate information, regardless.
  • How hard you’re willing to work to get the credible, timely information that suits your purpose. (What you’re learning here will make it easier.)

Thus, your standards for relevance and credibility may vary, depending on whether you need, say,:

  • Information about a personal health problem.
  • An image you can use on a poster.
  • Evidence to win a bet with a rival in the dorm.
  • Dates and times a movie is showing locally.
  • A game to have fun with.
  • Evidence for your argument in a term paper.

For your research assignments or a health problem, the consequences may be great if you use information that is not relevant or not credible.

Evaluating for Relevance

Relevant sources are those that pertain to your research question. You’ll be able to figure that out fairly quickly by reading or skimming particular parts of sources and maybe jotting down little tables that help you keep track. We’ll show you how below, including where to look in specific kinds of sources and what questions to ask yourself as you do.


One thing to consider early on as you make inferences about relevancy is the effect that timeliness, or a source’s currency, should have on deciding whether a source is relevant. Your research question will determine that.


For instance, if your research question is about the life sciences, you probably should consider only the most recent sources relevant because the life sciences are changing so quickly. There is a good chance that anything but the most recent sources may be out of date. So aim for sources no more than 5 years old. (An example discipline that calls for even newer sources is computer security.)


But suppose your research question is about the Edo Period in Japan (1603-1868) or about Robert Falcon Scott, who explored the Antarctic from 1901-1913. In these cases, an item from 1918 might be just as useful as an item from 2018 (although new information may have been found in the 100 year gap). But something from 1899 about Antarctica or from 1597 about Japan would NOT be current enough for these research questions.


These example research questions also give you two more clues about how to treat the timeliness or currency of sources as you consider relevance:

  • Because of how long ago they lived or occurred, it would be unusual for many sources on Robert Scott or the Edo Period to have been published very recently. So, unlike sources for the life sciences, whether a source is very recent should probably not determine its relevancy to those research questions.


  • Primary sources might be considered especially relevant to all three research questions. Life science journal articles that provide research findings for the first time count as primary sources. And primary sources (such as Scott’s diaries and expedition photographs, as well as paintings, literature, clothing, and household items from the Edo Period) go a long way to explain faraway people and times. (See Primary, Secondary, & Tertiary Sources.)

The information in the tabs to the right tells where to look and what questions to ask yourself to assess three kinds of sources’ relevancy to your research question: websites, articles, and books. Whatever you do, don’t stop evaluating a source after looking only a website’s name or the title of another source.

Save time by looking in particular places in sources for information that will help you figure out whether the source is relevant to your research project. Much of our advice here comes from “Speedy Reading” in The Craft of Research, second edition, by Wayne Booth, Gregory Colomb, and Joseph Williams, 2003, pp. 108-109.

On a website, check the name of the website and its articles for clues that they contain material relevant to your research question. Consider whether time should have an impact on what information can be considered relevant. If so, skim any dates, datelines, What’s New pages, and press releases to see whether any website content works with the time considerations you need. Page creation or revision dates that you find can also help.


Skim any site map and index on the website for key words related to your research question. Try the key words of your research question in the search box. Do you see enough content about your keywords to make you think parts of the website could be helpful?

For an article, think about the title. Does it have anything to do with your research question? Consider whether time should have an impact on what sources can be considered relevant. If so, is the publication date within your parameters? Also skim the abstract to see whether the article works with the time considerations you need. For instance, if there is a time period in your research question, does the article address the same time period or was it created in that time period?


Look at the abstract and section headings in the article to locate the problem or question that the article addresses, its solution, and the outline of the article’s argument for its main claim. Can those help answer your research question? Do they make it seem the article will give you information about what others have written about your research question? Do they offer a description of the situation surrounding your research question?


Do the article’s introduction and conclusion sections help you answer your research question and/or offer a description of the situation surrounding your question so you can explain in your final product why the question is important? Check whether the bibliography contains keywords related to your research question. Do the sources cited by the bibliography pertain to your research question?

For a book, check whether the title indicates the book could be about your research question. Consider whether time should have an impact on what sources can be considered relevant. If so, is the publication date or copyright date (usually listed in the library catalog or on the back of the book’s title page) too early or late for any time constraints in your research question? Maybe it is just right. Also skim some of the preface and introduction to see whether the book works with the time considerations you need.


For help answering your research question, skim the book’s table of contents and any summary chapters to locate the problem or question that the book addresses, its solution, and the broad outline of the book’s argument for its main claim. Do they also give you information about what others have written about your research question? Do they offer a description of the situation surrounding your research question? Look for your key words in the bibliography. Do the sources cited pertain to your research question? Skim the index for topics with the most page references. Do the topics with the most page references pertain to your research question?

Evaluating for Credibility

Once you've evaluating a source for relevancy, you are ready to evaluate it for credibility.

What are the clues for inferring a source’s credibility? Let’s start with evaluating websites, since we all do so much of our research online. But we’ll also include where to find clues relevant to sources in other formats when they differ from what’s good to use with websites. Looking at specific places in the sources will mean you don’t have to read all of every resource to determine its worth to you.

And remember, the more you take these steps, the faster it goes because always examining your sources becomes second nature.



What Used to Help

It used to be easier to draw conclusions about an information source’s credibility, depending on whether it was a print source or a web source. We knew we had to be more careful about information on the web–simply because all the filters that promoted accuracy involved in the print publishing process were absent from most web publishing. After all, it takes very little money, skill, and responsible intent to put content on the web, compared with what has to be done to convince print publishers that your content is accurate and that they will make money by printing it.

However, many publishers who once provided only print materials have now turned to the web and have brought along their rigorous standards for accuracy. Among them are the publishers of government, university, and scholarly (peer-reviewed) journal websites. Sites for U.S. mainline news organizations also strive for accuracy rather than persuasion–because they know their readers have traditionally expected it. All in all, more websites now take appropriate care for accuracy than what used to be true on the web.

Nonetheless, it still remains very easy and inexpensive to publish on the web without any of the filters associated with print. So we all still need the critical thinking skills you’ll learn here to determine whether websites’ information is credible enough to suit your purpose.


5 Factors to Consider

Evaluating a website for credibility means considering the five factors below in relation to your purpose for the information. These factors are what you should gather clues about and use to decide whether a site is right for your purpose.

  • The source’s neighborhood on the web.
  • Author and/or publisher’s background.
  • The degree of bias.
  • Recognition from others.
  • Thoroughness of the content.

How many factors you consider at any one time depends on your purpose when seeking information. In other words, you’ll consider all five factors when you’re looking for information for a research project or other high-stakes situation where making mistakes have serious consequences. But you might consider only the first three factors at other times.

To understand this concept and begin to use it, imagine that all the sites on the web constitute a community. Just like in a geographical community, there are neighborhoods in which individual sites hang out.

Thinking about what neighborhood a source is in on the web can help you decide whether the site is credible and suits your purpose.


The Outernet


Viewing the web as community. Image source: John Atkinson, Wrong Hands


Audio: Neighbourhoods on the Web

Listen to the audio clip (or read the text version) to hear how intuitive this concept is.

Listen to Audio    |      View Text Version


Clues About a Website's Neighbourhood

On a website, check pages labeled About Us, About This Site, Mission, Site Index, and Site Map, if available. (If such pages or similarly labeled ones don’t exist, it may be a sign that the site may be less trustworthy.)

Ask yourself these questions to gather clues that will help you decide what neighborhood you’re in:

  • Is the site selling products and/or services (even if there are articles and other useful information, too)? Perhaps it’s a retail, service center, or corporate site.
  • Are there membership applications and requests for contributions of money or time anywhere on the site? They’re usually a sign that you’re on a site that promotes particular ideas or behavior – in other words, they’re in the advocacy neighborhood.
  • Do postings, articles, reports, and/or policy papers give a one-sided view or multiple views on issues, people, and events? If they’re one-sided, the site is probably a commercial site or in the advocacy group neighborhood. If the information is even-handed and includes different sides of an issue, the site is more likely to be on the library/museum, school, or mainline news side of town. Sites there usually provide information designed to educate rather than persuade. Newspapers online or in print usually do have editorial pages, however. But labeling opinions as such helps keep mainline news sources in the newsstand neighborhood and out of the advocacy neighborhood.


You’ll always want to know who’s providing the information for a website or other source. Do they have the education, training, or other experience that make you think they are authorities on the subject covered? Or do they just have opinions?

The more you know about the author and/or publisher, the more confidence you can have in your decision for or against using content from that source.

Authors and publishers can be individuals or organizations, including companies. (Web masters  put things on the site but do not usually decide what goes on all but the smallest websites. They often just carry out others’ decisions.)

Sites that do not identify an author or publisher are generally considered less credible for many purposes, including for term papers and other high-stakes projects. The same is true for sources in other formats.



Clues About an Author or Publisher's Background

If they’re available, first take a look at pages called such things as About This Site, About Us, or Our Team first. But you may need to browse around a site further to determine its author. Look for a link labeled with anything that seems like it would lead you to the author. Other sources, like books, usually have a few sentences about the author on the back cover or on the flap inside the back cover.

You may find the publisher’s name next to the copyright symbol, ©, at the bottom of at least some pages on a site. In books the identity of the publisher is traditionally on the back of the title page.


Sometimes it helps to look for whether a site belongs to a single person or to a reputable organization. Because many colleges and universities offer blog space to their faculty, staff, and students that uses the university’s web domain, this evaluation can require deeper analysis than just looking at the address. Personal blogs may not reflect the official views of an organization or meet the standards of formal publication.

In a similar manner, a tilde symbol (~) preceding a directory name in the site address indicates that the page is in a “personal” directory on the server and is not an official publication of that organization. For example, you could tell that Jones’ web page was not an official publication of XYZ University if his site’s address was: The tilde indicates it’s just a personal web page—in the Residences, not Schools, neighborhood of the web.


Unless you find information about the author to the contrary, such blogs and sites should not automatically be considered to have as much authority as content that is officially part of the university’s site. Or you may find that the author has a good academic reputation and is using their blog or website to share resources he or she authored and even published elsewhere. That would nudge him or her toward the Schools neighborhood.

Probably all sources exhibit some bias, simply because it’s impossible for their authors to avoid letting their life experience and education have an effect on their decisions about what is relevant to put on the site and what to say about it.

But that kind of unavoidable bias is very different from a wholesale effort to shape the message so the site (or other source) amounts to a persuasive advertisement for something important to the author.

Even if the effort is not as strong as a wholesale effort, authors can find many—sometimes subtle—ways to shape communication until it loses its integrity. Such communication is too persuasive, meaning the author has sacrificed its value as information in order to persuade.

While sifting through all the web messages for the ones that suit your purpose, you’ll have to pay attention to both what’s on the sites and in your own mind.

That’s because one of the things that gets in the way of identifying evidence of bias on websites is our own biases. Sometimes the things that look most correct to us are the ones that play to our own biases.

Clues About Bias

Review the website or other source and look for evidence that the site exhibits more or less bias. The factors below provide some clues.


Unbiased: This source’s information is not drastically different from coverage of the topic elsewhere. Information and opinion about the topic don’t seem to come out of nowhere. It doesn’t seem as though information has been shaped to fit.

Biased: Compared to what you’ve found in other sources covering the same topic, this content seems to omit a lot of information about the topic, emphasize vastly different aspects of it, and/or contain stereotypes or overly simplified information. Everything seems to fit the site’s theme, even though you know there are various ways to look at the issue(s).

Citing Sources

Unbiased: The source links to any earlier news or documents it refers to.

Biased: The source refers to earlier news or documents, but does not link to the news report or document itself.


Unbiased: Statements are supported by evidence and documentation.

Biased: There is little evidence and documentation presented, just assertions that seem intended to persuade by themselves.

Vested Interest

Unbiased: There is no overt evidence that the author will benefit from whichever way the topic is decided.

Biased: The author seems to have a “vested interest” in the topic. For instance, if the site asks for contributions, the author probably will benefit if contributions are made. Or, perhaps the author may get to continue his or her job if the topic that the website promotes gets decided in a particular way.

Imperative Language

Unbiased: Statements are made without strong emphasis and without provocative twists. There aren’t many exclamation points.

Biased: There are many strongly worded assertions. There are a lot of exclamation points.

Multiple Viewpoints

Unbiased: Both pro and con viewpoints are provided about controversial issues.

Biased: Only one version of the truth is presented about controversial issues.

Checking to see whether others have linked to a website or tagged or cited it lets you know who else on the web recognizes the value of the site’s content. Reader comments and ratings can also be informative about some sites you may be evaluating, such as blogs.

If your source is a print book, the blurbs on the front or back cover give you information from authors, experts, or other well-known people who were willing to praise the book and/or author. The same kind of “mini-reviews” may be available on the publisher’s website. You can also look for reviews of the book or other source by using Google and Google Scholar.

Those links, tags, bookmarks, citations, and positive reader comments and ratings are evidence that other authors consider the site exemplary. Book reviews, of course, may be either positive or negative.

Exactly which individuals and organizations are doing the linking, tagging, citing, rating, and commenting may also be important to you. There may be some company you’d rather your site not keep! Or, maybe the sites that link to the one you’re evaluating may help solidify your positive feelings about the site.

Don’t let an absence of links, tags, citations, ratings, and comments damn the site in your evaluation. Perhaps it’s just not well-known to other authors. The lack of them should just mean this factor can’t add any positive or negative weight to your eventual decision to use the site—it’s a neutral.


Citation as Recognition

In scholarly work in particular, assessing how much a work like an article has been cited can provide clues about the quality of the work. Here are some ways to check on the citations of a piece of work.


For articles published in scholarly journals, you can use Google Scholar to enter the title of the article in quotes. In the results list, find the article you’re evaluating. (Many articles have similar titles.) Look for the number of citations in the lower left of the listing for your article. If you want more information on the authors who have done the citing, click on the citation number for a clickable list of articles or papers and get the names of authors to look up at the end of the articles or with a search engine. (This is a good way to discover more articles about your topic, too.)





You can also search in specialized databases like Web of Science or Scopus (search for either in the Library Catalogue



Figuring out whether a website or other source is suitable for your purpose also means looking at how thoroughly it covers your topic

You can evaluate thoroughness in relation to other sources on the same topic. Compare your source to how other sources cover the material, checking for missing topics or perspectives.


Clues About Thoroughness

Click around a site to get some idea of how thoroughly it covers the topic. If the source you are evaluating is a print resource, read the introduction and conclusion and also the table of contents to get a glimpse of what it covers. Look at the index to see what subject is covered with the most pages. Is it thorough enough to meet your information need?