There is no simple formula for evaluating sources; evaluation always depends on the facts of your own rhetorical situation.
Here is a basic framework you can use to evaluate your rhetorical situation and analyze how well your sources support it:
1. Is the source useful to you?
Does it provide the kind of information you need?
Does it meet your assignment requirements?
Does it make you think? Did it spark further questions or suggest additional lines of inquiry?
Does it help you contextualize or understand other sources?
2. Is this the type of source your audience expects you to use?
Is it at the right level — not too difficult nor too easy for your audience?
Will it give you more credibility with your audience if you use it?
If you are not sure about what your audience expects, how can you find out?
3. Who created the source?
Is the author identified AND if they are, are they someone you find credible?
If the author is not identified, is there a group or institution responsible for the source? Do you find that group credible?
Have you done whatever additional research you need to do to decide if the author is credible or useful?
4. What is the author’s (or institution’s or agency’s) purpose in creating this source?
Are they trying to persuade you to do or think something specific?
Are they selling something?
Does their purpose or agenda affect the quality of their evidence? Did it affect how they presented it?
Do they articulate their agenda themselves?
Does what they say about their agenda match what others say?
5. (If the source is a scholarly one) is it a good example of research in the discipline?
NOTE: For many of these questions, you may need help figuring out the answers. Do you know enough about research in this discipline to answer this question? Asking professors in the field, or librarians who work with this literature, may help.
Do they use citations, footnotes, etc. to connect their work to the rest of the field?
Is the source referenced (used and cited) by other scholars you’ve found?
Is it current enough to meet your needs?
Was it published in a journal or other source important in the field? How do you know?
(This framework is adapted from one created by Oregon State University librarian Anne-Marie Deitering in The Academic Writer, by Lisa Ede)
Watch: “Evaluating Sources to Find Quality Research”
This video (5:28) will help you consider three questions you should ask in of any source you find in your research.