Authority refers to the reputation and / or expertise of the source's author (often the source's publisher, too).Learn more
Authority isn't enough on its own, and even experts get it wrong sometimes. What else makes the source reliable?Learn more
Purpose refers to the intent of the information. Is the source trying to convince you of something? Is the source a response to previous research in the area? Is the source a response to a lack of information in a specific area?Learn more
In most cases, you should look for sources published in the last 5-10 years. If you're writing about something that happened in the past, though, older sources might be helpful.Learn more
These criteria should be used together.
This is probably obvious, but before you evaluate your sources, you need to have sources to evaluate.
If you don't have any sources yet, you can start from the search box on the library homepage.