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Public Health

Guide to library research for evidence-informed public health practice.


Evaluating your sources is a crucial step of the information research process. 

  • Critical appraisal is the process of assessing the quality of research study methods to determine if the reported outcomes are trustworthy, meaningful and relevant to your situation. Critical appraisal checklists are available to help you evaluate research studies in the form of intervention studies, observational studies, qualitative research, systematic reviews, and more.
  • Specific evaluation criteria to consider for grey literature sources is provided further down the page followed by general considerations for evaluating information by means of two different (but similar) checklists that you can apply.

Appraising Grey Literature

Public Health Ontario guide to appraising grey literature:

Consideration of the presence (reporting) and the appropriateness (validity) of the items described below will help to assess the quality of the item. It is also recommended to consult with colleagues when possible. 



Facts and references



Who is the author, are they who they claim to be?

Does the hosting site have a sponsor?

Are references included?

Is a publication or revised date provided?


Does the author/host have an agenda? Publishing body:

  • Are they a well-known provincial/national government-affiliated public health agency?
  • For-profit company?
  • Political or philosophical agenda? (e.g. Fraser Institute vs. Canadian Centre for Policy Alternatives)

Is the information shared for commercial purposes?

Does the site sponsor have a political or philosophical agenda?

Are references to research evidence?

Is the information based on research/data/analysis or is it opinion piece?

Can you verify some cited sources, facts?

How current are the references?

Is the information current?

(Ontario Agency for Health Protection and Promotion, 2015)

Evaluating Sources Checklist

The following checklist can be used to appraise both scholarly and non-scholarly sources.

Purpose Why was the resource written? Was the author's purpose to inform, persuade, or to refute a particular idea or point of view?
Audience Is the resource intended for the general public, scholars, professionals,etc.
Authority What are the author's qualifications? Consider author's educational background, past writings and experience. Is the author associated with an organization or institution? Who is the publisher? Are they well known? Does any group control the publishing company?
Accuracy Is the information covered fact, opinion, or propaganda? Facts can be usually verified. Opinions evolve from the interpretation of facts. Are the author's conclusions or facts supported with references?
Timeliness When was the information published? Is the date of publication appropriate for your topic?
Coverage Is it relevant to your topic? Is the topic covered in depth, partially or is it an broad overview? Does the resource add new information, update other sources or substantiate other resources that you have consulted?
Objectivity Does the author present multiple viewpoints or is it biased? How do critical reviews rate the work?

CRAAP Checklist for Evaluating Web Resources

It's easy to find information on most any topic on the Web but whether the information found is reliable, up-to-date and unbiased is the question researchers face. Since anyone can post anything on the Web, it is very important to critically examine the information and the website. The CRAAP Test is a list of questions to help researchers evaluate sources of information. It is a tool to help you think critically about the quality of health information.


  • When was the information published or posted?
  • Is it current enough for your topic?
  • Has it been revised or updated?


  • Does the information relate to your topic or answer your question?
  • Who is the intended audience?
  • Is the information at an appropriate level (i.e. not too elementary or advanced?)
  • Have you looked at a variety of sources before determining to use this one?
  • Are the topics included explored in depth?


  • Who is the author or creator?
  • What the author's qualifications or credentials in writing about this subject?
  • How reputable is the publisher?
  • Are there organization affiliations? Are they reputable?
  • Does the information provide references or sources of data? 


  • Where does the information come from?
  • Is the information supported by evidence?
  • Has the information been reviewed or refereed?
  • Can you verify the information in another source or from personal knowledge?
  • is the content primarily opinion? Or is it balanced with multiple points of view?
  • Does the language or tone seem unbiased and free of emotion?


  • What is the purpose of the information? Is it to inform, teach, sell, entertain or persuade?
  • Do the authors make their intentions or purpose clear?
  • Is the information fact, opinion or propaganda?
  • Does the point of view appear objective and impartial?
  • Are there political, ideological, cultural, religious, institutional or personal biases?

The CRAAP Test was developed by a librarian at California State University, Chico.