“There is a grand consensus among all walks of academia that with the infinite variety and levels of scholarship on the Internet, the evaluation of information is one of the most important skills that we, as librarians and instructors, can teach our students.“

Those are the words of Sarah Blakeslee, the woman who invented CRAAP. It's the most widely used acronym for what to check before trusting a source.

Librarian at the Meriam Library at California State University, Chico, Sarah wanted an easy way to remember the variables that we should all consider when deciding whether to trust and use the source we’ve just found.

C is for Currency: a judgement about whether the information in the text is up to date or has become outdated because of advances in the field.

R is for Relevance: a judgement about whether the content is relevant to your purpose.

A is for Authority: a judgement about whether the author and/or publisher has enough expertise on the subject to be trusted.

A is also for Accuracy: a judgement about how accurate the information is.

P is for Purpose: a judgement about how biased the content might be, based on why the content was created.

For each of the five variables, there are questions we can ask.

Used well, the CRAAP test helps protect us against bad sources that make us less credible if we use them.

Here are a few tips that can make it easier to answer some of the CRAAP test questions:


  • Information becomes outdated more rapidly in some fields than others.
  • If the document doesn’t have a date associated with it (usually at the beginning or end of the document), don’t assume that the copyright date for the web page is the same as when the content was published. Although it shouldn’t be, the copyright date at the bottom of a page can be changed without updating what is copyrighted.
  • This technique posted by William Stanton gets Google to tell you when a page was published:
    • Open the Google search page,
    • Type inurl: in the address bar,
    • Paste the URL of your undated webpage after inurl:
    • Hit Enter,
    • Type &as_qdr=y15 at the end of the new URL,
    • Hit Enter and the date should now appear in the search result



  • Sometimes a text isn’t relevant but can still be useful:
    • It might use some key words for the topic that we can use to make a better search query in Google.
    • If it includes references, there may be a source among them that is more relevant.



  • When an author’s education and experience relate to the topic, those credentials are usually mentioned near the author’s name. When they don’t relate to the topic, there is more chance that no information about the author’s education and experience will be given.
  • A relevant Ph.D. is worth more than a relevant Masters, which is worth more than a relevant Bachelors.
  • Years of relevant experience can be as valuable as, or more valuable than, university degrees.
  • Reputation can affect authority. Googling the author’s name sometimes reveals factors that help determine whether the person has a good reputation. But be sure that you have found the right “John Doe”.
  • Companies and organizations are authors too.
  • When no author is given for web page content, the website (i.e., company, organization or individuals behind it) should be considered the author.



  • As you come to know more and more about your field of study, don’t forget to use your own knowledge of a topic to evaluate how accurate the information in a source is.
  • We also need to be aware of persuasive techniques or strategies that can influence our judgments about accuracy. Martin Thibault's list of 36 common techniques presents both the good and the sneaky.
  • The University of North Carolina at Chapel Hill's Writing Center offers this list of logical fallacies that can weaken a source's content. Get to know as many as you can and you'll be better at deciding who to believe.



  • PIE is a helpful acronym for remembering the common purposes that texts have:
    • Persuading
    • Informing
    • Entertaining

Any combination of those can be what the author intends for the text’s audience.


Useful links: