Same as always. You evaluate the quality and source bias of the observations, reports or experiments. You try to reproduce the results of whatever. You develop a credible body of evidence that is as objective as possible and formulate conclusions and make an honest effort to recognize and understand opposing arguments: without challenging your conclusions you can not validate them. Recognize that your own perceptions and the perceptions of people you trust are often colored by biases and factor that in. In the end you have to decide if there is sufficient trust-worthy evidence to believe something, and even then recognize that you could be wrong. Unfortunately there are some who just accept whatever the political party or the union or the news-organization-I-like-today says or publishes as if it was fact. Many people lack useful critical thinking skills leading to all kinds of nonsensical beliefs in areas of philosophy, politics, science and others. Lies and distortions repeated often enough are broadly accepted as fact - beware of these things. To demonstrate some of these influences: in the news recently was a survey that a shocking number of people who read "The DaVinci Code" or saw the movie believe that it is fact when most of the crucial details presented are demonstrably fiction. The idea that someone could read a novel and without any fact-checking accept it as truth is disturbing, but a symptom of a common problem in modern society.

My position is that you always have to question things - don't presume everything to be true, or false - don't "as is" things, including information you read/hear/see - do your own research. Glean informaton from several sources. PEEL THE LAYERS. Don't presume there ARE no layers. There ARE layers. Usually LOTS more than you would think, at first. Be a DETECTIVE: PROBE. SEARCH. QUESTION. WONDER. DON'T PRESUME. It's easy for me, it comes naturally: I'm a Scorpio, with a 140 IQ. Probing is like breathing, to me!!! That's why I'm too intense for so many people - except my 2nd husband, a Cancer w/ a Scorpio Moon who also has about a 140 IQ!!...