What source is most credible?

EB, Encarta, and the like are probably the most credible since they have paid staff to fact check and research everything, but a well written wikipedia article will have tons of references and resources to explore, so if I were researching a subject, I’d look at wikipedia’s footnotes and references and go from there.

Just seems to make more sense to me to find small places that specialize in certain types of information, than looking for the epic tome that tries to do everything and answers nothing.

I recall from a 60 Minutes or something that Wikipedia has an average of 4 errors per page while EB has 3.

If your going to debate I would advise you to take note of the apparent errors of all three, and follow sinscriven’s advice on the footnotes. The better you know where the disagreement on the subject is, the less likely your opponent will catch you off guard.

Also do a web search for other research, those sites you mentioned are for general information not for detailed debate winning.

Good Luck

If you really want to have good sources, you absolutely have to go beyond encyclopedia articles, no matter what encyclopedia you use. As said, check footnotes and go directly to the sources of the information and check scientific magazines (that is, general interest/general public publications that specialize in science) and even scientific journals (publications specifically aimed at scientists). And, of course, search for philosophical and ethical debates on the issue.

You might also want to check Arthur Schopenahuer’s The art of controversy

Use the information (especially the citations) in the Encyclopedia Britannica and Wikipedia and Encarta to find better sources. Encyclopedias are for getting a quick answer or a quick overview and for giving you starting points for further research.