Grey Literature for Health Sciences

How Do I Evaluate It?

To look at information critically means you approach it like a “critic”. You must question, analyse and contextualize your sources in order to make a decision about their value and appropriateness. Several factors or “critical lenses” can be used to assess information:

The CRAAP Test is a list of questions to help you evaluate the information you find. Different criteria will be more or less important depending on your situation or need.

  • Currency: When was the information published or posted? Has the information been revised or updated? Is the information current or out of date for your topic? Are the links functional?
  • Relevance: Does the information relate to your topic or answer your question? Who is the intended audience? Have you looked at a variety of sources before determining this is one you will use? Would you be comfortable using this source for a research paper?
  • Authority: Who is the author/publisher/source/sponsor? Are the author's credentials or organizational affiliations given? What are the author's credentials or organizational affiliations given? What are the author's qualifications to write on the topic? Is there contact information, such as a publisher or e-mail address? Does the URL reveal anything about the author or source? For examples: .com (commercial), .edu (educational), .gov (U.S. government), .org (nonprofit organization), or .net (network).
  • Accuracy: Where does the information come from? Is the information supported by evidence? Has the information been reviewed or refereed? Can you verify any of the information in another source or from personal knowledge? Does the language or tone seem biased and free of emotion? Are there spelling, grammar, or other typographical errors?
  • Purpose: What is the purpose of the information? To inform? Teach? Sell? Entertain? Persuade? Do the authors/sponsors make their intentions or purpose clear? Is the information fact? Opinion? Propaganda? Does the point of view appear objective and impartial? Are there political, ideological, cultural, religious, institutional, or personal biases?

Source: Library,  University of Ottawa. (n.d.). Evaluation criteria. Retrieved October 5, 2017, from

For more information on how to use the CRAAP test to evaluate grey literature watch this short 5:27 min video.

C.A.R.S. Checklist for Evaluating Internet Sources

The CARS Checklist (Credibility, Accuracy, Reasonableness, Support) is designed for ease of use. Few sources will meet every criterion in the list, and even those that do may not possess the highest level of quality possible. But if you learn to use the criteria in this list, you will be much better able to separate the high-quality information from the poor-quality information.

  • Credibility: Trustworthy source, the quality of evidence and argument, author’s credentials, evidence of quality control, known or respected authority, organizational support. Goal: an authoritative source; a source that supplies some good evidence that allows you to trust it.
  • Accuracy: Up-to-date, factual, detailed, exact, comprehensive, audience and purpose reflect intentions of completeness and accuracy. Goal: a source that is correct today (not yesterday); a source that gives the whole truth.
  • Reasonableness: Fair, balanced, objective, reasoned, no conflict of interest, absence of fallacies or slanted tone. Goal: a source that engages the subject thoughtfully and reasonably; a source concerned with the truth.
  • Support: Listed sources, contact information, available corroboration, claims supported, documentation supplied. Goal: a source that provides convincing evidence for the claims made; a source you can triangu-late (find at least two other sources that support it).

Source: McGraw-Hill Higher Education. (20003). The CARS Checklist (Credibility, Accuracy, Reasonableness, Support). Retrieved October 5, 2017, from