Distinguishing fact from fiction: when faced with an overload of misinformation being peddled through the media and Internet, the application of common-sense principles can help sort fact from fiction.

With rumors and urban legends circulating more frequently and reaching greater numbers of people, it is more important than ever to learn to tell the difference between fact and fiction and truth and falsehood. In doing so, consider the following points:

* Consider the source. A primary key is to know the track record of the source. When a source repeatedly makes claims that turn out to be false, that source is unreliable. When evaluating information published by sources with unreliable track records, make sure to check the accuracy of the information against other, reliable sources. If you're not sure about the track record of a source's reliability, consider whether the source stands to gain by saying what they're saying (or their financial backers stand to gain).

* Consider the evidence. Extraordinary claims require extraordinarily convincing evidence. Generally speaking, in an article meant to be persuasive, there should be at least three pieces of credible proof backing the assertions being made (preferably proof from several different reliable sources). If the speaker or publication makes astonishing claims but cites mostly anonymous sources, look out. The information may be valid, but withhold judgment until confirmation is possible. There are times when quoting an anonymous source is appropriate, but such citations should be used very sparingly and only when absolutely necessary. Note, too, whether the information is current and needs to be current. Also, quotes and statistics should be verifiable.

* Ensure that the facts support the conclusion. Sometimes factual information is used to support outrageous allegations. The black helicopter rumors of the mid-1990s are a case in point. The black helicopter conspiracy argument, in essence, states: "black helicopters exist and have been used to support, for instance, UN military operations. Therefore, all black helicopter sightings confirm the presence and activity of nefarious UN personnel." The fact is that the U.S. military uses helicopters painted in dark color schemes and that these have been used to support UN operations. It does not follow from this, however, that all black helicopter flights are traceable to the UN.

* Beware of appeals to worst fears. Very often the rumors that draw the greatest interest are those that seem to confirm our worst fears. Frequently purveyors of stories that fly in the face of evidence or reason resort to abject sensationalism to maintain a reader's or listener's interest.

* Learn to apply Oekham's razor. The medieval philosopher William of Ockbam codified and popularized the doctrine of parsimony that states, in its most basic form, that the simplest explanation that fits the observed phenomena is the best. As an example of the application of this principle, consider the 9/11 attack on the Pentagon. Of the undisputed facts, it is known that an airliner was hijacked, that the airliner disappeared, and that the Pentagon suffered severe impact damage following a sufficient interval of time during which the hijacked aircraft could have made its way to Washington. A popular theory holds that the Pentagon was attacked by a missile. What then happened to the plane? To account for its disappearance, the permutations of this theory hold various, unconfirmed opinions about what could have happened to the plane. The competing theory, that the plane crashed into the Pentagon, is far simpler. It accounts for the hijacking, the loss of the plane, and the damage to the Pentagon without the introduction of numerous and unnecessary "what ifs" and "maybes."

* Consider whether the proof given is really proof at all. Many times so-called proof is really just character assassination or name-calling. When George H.W. Bush competed in the Republican primaries against Ronald Reagan, Bush rarely debated the merits of Reagan's "Trickle Down" theory of economic wealth. If the subject of economic plans came up, Bush simply called Reagan's initiatives "voodoo economics." Use this same reasoning when evaluating quotes or statistics. Often quotes are used out of context or statistics are misrepresented or based on a flawed study.