RELIABILITY is the most important factor to consider for ANY source!
DO NOT get trapped by confirmation bias - check many sources!
If your source of information is not reliable, you cannot trust the information.
(Video on evaluating sources) (Evaluating web sites)
To check RELIABILITY of a source:
1. Think about whether or not the information makes sense
2. Gather author/publisher info
If you cannot find an author's name AND publishing information, your source is probably not legitimate or reliable. This is why web sites (especially Wikipedia) are a dangerous source of information - anyone can post information to the internet, and little of it is checked for quality.
The exceptions to this rule are:
Information from well-known news sources (papers, magazines, web sites) that list AP or Reutersas the author. These are well-known, reliable news services (they gather news from many sources and aggregate it [compile it in one location]).
Governmental organizations' web sites (their URLs end with .gov)
Educational institutions' web sites (their URLs usually end in .edu)
3. Use author name to check whether she/he is reliable (other works in print raises probability of reliability)
4. Use publisher info to see if publisher is well-known/reliable/up-to-date (each one of these raises probability of reliability)
5. Check info against other sources to see if sources all agree
a. Books
b. Magazines
c. The internet (be careful!)
d. People, esp. experts
6. Try to get most recent info – more likely to be correct (IF the source seems reliable)