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.
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.
Authority: The source of the information.
Accuracy: The reliability, truthfulness and correctness of the content.
Purpose: The reason the information exists.
Adapted from: Blakeslee, S. (2010). Evaluating Information – Applying the CRAAP Test. Retrieved from http://www.csuchico.edu/lins/handouts/eval_websites.pdf