Paraphrased from the Chapter "The Fine Art of Baloney Detection" in the book by Carl Sagan The Demon-Haunted World, Science as a Candle in the Dark, 1996

These are some of the tools used by the scientist to help find the truth:

1. Independent confirmation - can others repeat the experiment in their own lab?
2. Debate your ideas with others knowledgeable in this area. Different points of view can strengthen your ideas
3. Beware of arguments from authority. They can be wrong. Look carefully at their reasoning, not who they are
4. Consider more than one hypothesis. This will exponentially expand the number of experiments you can use to test your ideas
5. Avoid attachment to one hypothesis
6. Quantify your results — it will then be easier to compare results with other experiments and other researchers
7. Every link in your chain of reasoning must hold, not just the final result. Look for weak links to better test your ideas
8. Is your hypothesis testable? The support of a hypothesis comes from the test of many trials

Be careful of arguments:

1. that attack the arguer and not the reasoning behind the work/ideas
2. that depend on who said it rather than the reasoning
3. that you accept because it is easier than "fighting" the system
4. that are not logically explained and understandable
5. that are not supported by data
6. that select only the observations that fit the hypothesis
7. that depend on small numbers of samples or trials. Repeatability is essential
8. that depend on misuse of or manipulation of statistics (Also know as "gee wiz graphics")
9. that are inconsistent. Using the same argument to support two viewpoints
10. that fail to recognize other possibilities
11. that correlate with no supporting evidence of causation
12. that exclude the middle possibilities (extremes in values, time, consequences)
13. that depend on suppressed evidence or half-truths
14. that use "weasel words" to avoid telling it like it is (really a way of lying!)