Skip to main content

BIOL 212: Principles of Biology

Resources for Biology 212

Evaluating Information Sources

Use critical thinking to decide when information is useful, trustworthy, and relevant.

Not all information is created equal

Searching and locating information sources is only one part of the research process. An equally important part is being able to tell if the sources you've located are trustworthy, appropriate, and authoritative.

Sliding Scales

Source evaluation is along sliding scale, not black or white, good or bad. While there are some sources a majority will agree are "good" or "bad" most information falls somewhere in between these two extremes and it's up to YOU to make a final decision.

How Much You Can Trust a Bearded Man?
A silly example of a sliding scale, The Trustworthiness of Beards by Matt McInerney. Click to enlarge.

How you use information will determine if it is "good" or "bad."

Evaluating Sources with the C.R.A.P. Test

The CRAP Test asks you to evaluate information sources across four dimensions: Currency, Reliability, Authority, and Purpose. Below each dimension are some questions to ask about your source as you evaluate it. At the bottom of the page you'll find links that explain some of these concepts in more detail.


Is the source up-to date?
  • How current is the information? Is it outdated?
  • How old are the references/citations, are they out-dated?
  • Is it current enough for your topic?


Is the source accurate?
  • What kind of information is it?
    • Is it a primary or secondary source?
    • Is it a popular or scholarly source?
  • Is the content balanced or biased?
  • Are there references or citations?
    • Are the citations reliable?
    • Are they current?
  • Was it peer reviewed?


Is the author trustworthy?
  • Who wrote or created it? (persons or organization)
  • What are their credentials?
    • education, affiliation/employer, experience, etc.
  • Who is the publisher/sponsor/host?
    • Are they reputable?
    • What kinds of things do they publish? (scholarly, news, entertainment, etc.)


Why was it created?
  • To teach, educate, or inform? 
  • To persuade?
  • To sell or promote?
  • To argue a side? 
  • To entertain?

Adapted from the original CRAP test. 

More Help Evaluating Sources

Your Librarian

Heather Lewin's picture
Heather Lewin
150 Parks Library
(515) 294.1004