Evaluating information sources is an important part of the research process, and it can be done quite easily with the CRAAP test.
CRAAP is an acronym for:
 urrency |
 elevance |
 uthority |
ccuracy |
 urpose |
Currency
Do I need current or historical information, or both?
Most of the time, your research requires you to find current information or data, but you may sometimes need to find information about the past.
When was the information published?
Check the date of publication of the book or article. If you are using an online source such as a webpage, check the last update date.
Has the information been revised or updated?
Is it a time-sensitive topic? If so, is the data or information the most recently available?
Relevance
Is the information related to my topic?
Make sure that you do not misinterpret the topic. Be very clear about what are the information which you need to gather to address the topic.
Who is the intended audience?
Is the information meant for lay people or those who are experts in the field?
Is the information too simple or advanced for my assignment, or just right?
Very often, scholarly, peer-reviewed articles are not easy to understand and you may need to read them a few times. Read the abstract and conclusion to get a gist of the content before reading the article.
Authority
Credentials
What are the qualifications or experience of the author? Who is the publisher of the book or article? Is there a sponsor for the research or experiment? Does that skew the research hypothesis or findings?
Affiliations
Which organisation or institution does the author belong to?
Contact details
Does the article or book contain contact information which allow you to confirm the author's credentials and affiliations?
Accuracy
Is the information free from errors?
This can be determined by checking if different sources agree on the information or data.
Has it been reviewed by peers?
If a book has been edited, or if an article has been peer-reviewed, the information is generally more accurate.
Is there supporting evidence? What is the origin of the information?
In general, a source which cites other sources of information can be considered to be more accurate and reliable.
Purpose
What is the purpose of the information?
Is the resource meant to entertain, inform, persuade or sell? Try to ascertain whether the information presented is an opinion, fact or propaganda.
Video on CRAAP
How library stuff works: The CRAAP Test by McMaster Libraries