what are the pros and cons of the various methods of conducting psychological research

Please put subject in the subject box when asking for help, it is a great waste of time for each instructor to sort through these, then find a topic in which the student who has done no research.

Fifth graders can do Google searches.
http://www.google.com/search?q=+what+are+the+pros+and+cons+of+the+various+methods+of+conducting+psychological+research+&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a