Examine the sources of information that the person or book or website uses. Do they have actual sources of information or are they just presenting material without giving any backing or citations? If they do reference sources, are they places of information that have authority? "Many people are saying," for instance, doesn't actually cite a real source, whereas "The Department of Housing and Urban Development reported _______" is offering strong source credentials.
Also examine the credentials of the author or website itself. Is the author someone with training and a track record in the subject being covered? (Example: A university professor in that subject area.) Does the website get cited by other agencies, or has the book or site been noted with any awards? "Bubba's Blog" is not as reputable or reliable as The New York Times.
Does the person or site seek to offer objective information, or is it biased toward the support of only a particular position or agenda? Sometimes the bias will be shown in the sponsors or backers of a particular book or site. Other times you can tell just by reading, that it only presents one side of an argument and does not take any other perspectives into consideration. It's fine to pay attention to sources that are biased, but then give attention to sources on BOTH sides of that bias, not just one side, so that you as a researcher can remain objective.
