Evaluating your sources is critical if you want to know if the information you found in a book, in an article or on the Web is good information you can use. If you're unsure where to start, the CRAAP Test (see below) is a great tool to point you in the right direction!
Currency: The timeliness of the information.
When was the information published or posted?
Has the information been revised or updated?
Does your topic require current information, or will older sources work as well?
If it is a website, are the links functional?
A microbiology textbook from 1950 might not be current because there has been a lot of progress in that field, but an insect identification manual from 1910 might be – depending on the topic.
Relevance: The importance of the information for your needs.
Does the information relate to your topic or answer your question?
Who is the intended audience? (General public? Researchers?)
Is the information at an appropriate level (i.e. not too elementary or advanced for your needs)?
Have you looked at a variety of sources before determining this is one you will use?
Would you be comfortable citing this source in your research paper?
Authority: The source of the information.
Who is the author/publisher/source?
What are the author's credentials or organizational affiliations?
Is the author qualified to write on the topic?
Is there contact information, such as a publisher or email address?
Does the URL reveal anything about the author or source? examples: .com .edu .gov .org .net
Accuracy: The reliability, truthfulness and correctness of the content.
Where does the information come from? Are there references?
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 unbiased?
Are there spelling, grammar or typographical errors?
Purpose: The reason the information exists.
What is the purpose of the information? Is it to inform, teach, sell, entertain or persuade?
Do the authors/sponsors 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?