Thinking Critically About Sources
Ohio State University Libraries Teaching & Learning
Evaluating sources for relevance, currency, and credibility is one of the most complex tasks you’ll do when working on a research project. Such sources will meet the information needs of your research project and make it possible for you to complete your final product.
In order to evaluate a source, you have to answer three questions about it. The first two are intertwined and answered pretty much at the same time as you’re looking for sources. Then you answer the third question about those sources that you have already decided are relevant and recent enough.
- Is this source relevant to my research question?
- Is this source recent enough (or created in the right time period)?
- Is this a credible source–a source my audience and I should be able to trust?
You should be able to answer “yes” to these three questions about each source you cite for a research project.
TIP: Other Criteria from Your Professor
Don’t forget that you also have to make sure your sources meet any other criteria that your professor may have given you for this assignment. For instance, professors often stipulate that some of your sources have to be scholarly sources or journal articles from a particular database. Professors in the humanities may also say that some of your sources must be primary sources. So, make sure you have identified enough of the kind of sources your professor has requested.
It’s important to determine relevance before credibility because no matter how credible a source is, if it’s not relevant to your research question it’s useless to you for this project. By the same token, a source that is not recent enough or not created in the right time period will also be unsuitable for your project, except perhaps for background information that you don’t cite.
You might already be worrying about how long evaluating sources is going to take. So let’s say right off that you won’t have to read all of every source to decide whether it is relevant, current or created in the right time period, and credible. (Later, of course, it will take a closer read to determine what direct quotes, paraphrases, and summaries you may want to use from the sources you have selected. We take that up in Chapter 7)
Regardless, our advice is to not begrudge the time you spend evaluating sources. It’s one of the most important things to learn in college—the opportunity to evaluate sources is one of the big reasons your professors assign research projects. And your future employers will expect you to have learned how to do it. For the rest of your professional and personal life, you will be using the critical thinking skills that make choosing the right sources possible. So taking the time to learn those skills is a great investment.
Happily, you’ll also get much faster the more you do it.
ACTIVITY: Evaluation Basics
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, much of the time it is inferences – educated guesses from available clues – that you have to make about whether a source is relevant, current, and credible.
That’s true even when your purpose is to answer the research question of your research assignment.
Your purpose 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 research project.
For your research assignments or a health problem, the consequences may be serious if you use information that is irrelevant, or out-of-date, or not credible.
Example Questions
| Information Need | What Kind of Information Will Help? | Weak Source | Strong Source | How Serious Are the Consequences if the Information Is Wrong? | How Much Work Is Worth Doing? |
|---|---|---|---|---|---|
| Information about a personal health problem | Accurate medical information based on research and expert knowledge | Health advice from TikTok or a personal blog | Mayo Clinic, CDC, NIH, or a healthcare professional | High. Incorrect information could lead to poor health decisions or delayed treatment. | High. It’s worth spending extra time to find reliable medical information. |
| An image you can use on a poster | An image that is relevant, high quality, and legal to use | An image copied from Google Images without checking permissions | Creative Commons images, Unsplash, Pixabay, or a library database | Moderate. Using a copyrighted image could lead to academic or legal issues. | Moderate. A little extra time can help you find a legal image. |
| Evidence to win a bet with a rival in the dorm | Facts that can be verified from a trustworthy source | A friend’s claim or a social media post | An encyclopedia, official statistics, or a reputable news source | Low. The consequences are usually minor, though accuracy still matters. | Low to Moderate. A quick check of a reliable source is usually sufficient. |
| Dates and times a movie is showing locally | Current and timely information | A friend’s memory of the showtime | The theater’s website or official movie app | Low. You might miss the movie or arrive late. | Low. The correct information is easy to find from an official source. |
| A game to have fun with | Reviews, ratings, and information about gameplay | An unknown download site with no reviews | Official app stores, Steam, or reputable gaming websites | Low. The main risk is wasting time or downloading unsafe software. | Low to Moderate. Reading a few reviews is often enough. |
| Evidence for your argument in a research project | Scholarly evidence, expert analysis, and credible data | Wikipedia, an opinion blog, or an online forum | Peer-reviewed articles, academic books, government reports, or professional association publications | High. Weak evidence can weaken your argument and affect your grade or credibility. | High. Strong research requires investing time in finding quality sources. |
Activity: Quick Check
Instructions: Select one answer to each question.
The degree to which a source can help you with your inquiry assignment or research project. If its content is related enough to your topic or research question that you can learn or quote from the source or paraphrase or summarize from it, it is relevant.
The timeliness of a source—whether it is recent enough or from the appropriate time period for your research.
The degree to which a piece of information can be believed. Credibility for a source probably cannot be perfect or guaranteed. But if credibility is high, the information is believed to be most likely true and reader/viewers can have confidence in it.
A term applied with different definitions, depending on the academic discipline. In the humanities and many other disciplines, a primary source is information that is firsthand, in its original form. We get primary source information without it having gone through any filter—no one translated it or told us what it meant. Examples of some sources that are often used as primary sources include diaries, breaking news stories, music and dance performances, artworks, eyewitness accounts, and journal articles that report research for the first time. But even those sources have to be actually used in research in order to become primary sources—nothing just exists as a primary source. The term primary source is used much less often in the sciences. When it does come up, scientists tend to use this term for the source, usually a research journal article, that was most important to their work.
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