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Information Literacy Tutorial

Our Library's tutorial covers: research skills, critical thinking and information literacy.

Credible Sources

Why is it necessary to critically evaluate information sources?

  • Evaluating information for research is just a specialized, advanced form of the same critical thinking skills you already use. No source of information is guaranteed to be trustworthy.  You always need to use your own educated judgment, even with scholarly articles from library databases.
  • Some sources of information are more trustworthy than others, but it can be hard to tell from appearances.
  • Evaluating information using critical thinking will save time and effort by filtering out materials you should not use. Your critical thinking will show up in your writing and you will get better grades.
  • Your professors may tell you to find credible information sources. This is a subjective term with many definitions, but the general consensus is that credibility is a combination of reliability, authority, validity and accuracy.


Reliability means that the entities that sponsored, supported, or published the information source have a reputation for quality, and integrity. The entity can be a journal, book publisher, movie studio, any kind of organization that puts information out on a website, etc.

In the case of a scholarly information source, like a scholarly journal article, you know:

  • It was either peer reviewed or editorially reviewed (and you can find out more by going to the publisher's or journal's website).
  • It was produced by a subject expert for an audience of subject experts.
  • It was produced for the purpose of informing and educating.

Plus, with scholarly information sources, it is easy to identify:

  • Who wrote it?
  • When was it written?
  • Who published it?

You can learn a lot about an information source by looking at the organization(s) responsible for producing it. Some questions to ask when encountering non-scholarly information sources:

  • Is their reputation for putting out good information their first priority, or do they have other priorities? In particular, be wary of any organization that is trying to sell something, raise money for something, win an election, win a court battle, win a war or win a battle of public opinion.


Authority means that the creator of the information source is an expert in the field. The creator can be an author, multiple authors, or an organization, government agency, company, etc.

Examine the creator's credentials

Author of a book or article:

  • Check out biographical information about the author wherever you can locate it. Look for book reviews or literary criticism of the author's work. Where has their work been published and in what type of publication? Articles in scholarly journals will include an author's credentials and references.

Company or organization as creator of online content:

  • Look for information about the company or organization on the website. Sometimes this is under an "About Us" link. You can also search the library databases to see what other information is available about the company or organization.



Validity asks the question, "How do we know what we know?"

Every field of study answers that question differently, but there are some ideas that are generally considered invalid, no matter whether an information source is scholarly or non-scholarly, and no matter what discipline or subject area it falls under.

Ideology, agenda and bias 

  • Ideology is a belief system shared by a group of people. Religions, political groups, and advocacy groups have ideologies. Not all ideologies are bad. And just because an author subscribes to an ideology does not mean that the information source necessarily has an ideological agenda. 
  • Agenda is a set of goals shaped by an ideology. If an information source has an agenda, that means it is not strictly informational or educational. It is probably actually a persuasive information source or a piece of propaganda, even if it is pretending to be otherwise.
  • Bias is the tendency of an information source to selectively over-emphasize some things and de-emphasize other things in such a way that it unfairly favors a certain conclusion or point of view. A credible information source will not try to tell you how to feel about the information.


Accuracy seems like the easiest of the criteria for judging an information source. Is the information presented correct, or not? It is a simple concept, but it does not necessarily have easy answer.

Verify against other information sources

You should already be using multiple information sources for your research, and you will notice discrepancies. If there are no discrepancies in the information, the source is probably accurate. If there are discrepancies, you need to decide which information source(s) you trust more, based on the other evaluative criteria.