When you evaluate material, look for high-quality information that is factual, reliable, well supported, current, verifiable, fair, and comprehensive.

Apply healthy skepticism, probing for erroneous or unreliable data. Reject claims that are based solely on anecdotes, testimonials, or opinions. Don't use just one source, because it might turn out to be wrong. Examine opposing viewpoints in an effort to find truth and to anticipate possible listener objections.

Be cautious in using polls because some people don't respond honestly, and results often depend upon how a question is asked.

Recognize the fallibility of experts. Don't assume that a Ph.D or M.D. is always trustworthy. Don't assume that affiliation with a prestigious university is assurance of credibility.

Watch out for groups with names that can mislead the public into thinking they are unbiased. Find out who is financially backing the group.

In analyzing Internet sites, watch out for subtle manipulation on Web pages. Examine domain names for clues on a source's objectivity and motivation. See if the material comes from a foreign country. If a Website has a beautiful, sophisticated design, don't assume that it is reliable and highly professional. Investigate its sponsors and authors to see if they are legitimate authorities on their subject matter.

Legally and ethically, it's important to give credit for material you derive from sources. Don't use copyrighted material unless you get permission from the copyright holder or unless the material falls into one of three categories: public domain, fair use, and royalty-free.