I can see why some people might long for the good old days, when medical advice came from your doctor, news from your local paper or Edward R. Murrow, and science news from a specialty publication like Scientific American. Today, we're overwhelmed with sources of information, with hundreds of television stations and millions of Web sites, and it can be hard to figure out what to trust. Google recently tweaked its search algorithm to bring higher quality sites to the top of its searches, but even then, how do you know what's good? Here are some questions to ask when evaluating the trustworthiness of science and health information (though many apply to other areas of life):
How far away is the information from its original source? Remember the game Telephone from your childhood, where a message would pass from one kid to the next, only to come out all garbled at the end? The same thing is true with most bits of information. The further you get from the original source (like a medical study), the more likely it is that what you read or hear has been misinterpreted. And if you can't determine what the original source was---as often happens when reading chain emails or random Web sites---it may be best to simply ignore it.
Who paid for the information? We should be skeptical about financial conflicts of interest when it comes to science and medicine. Several studies have found that funding from the pharmaceutical industry is associated with positive results, for example. But the funders of news and advice sites can also influence the information. The New York Times Magazine recently compared two sites with medical information---WebMD and MayoClinic.com---and concluded, "With the site’s (admitted) connections to pharmaceutical and other companies, WebMD has become permeated with pseudomedicine and subtle misinformation."
Is there any hype? If someone is claiming that they've found, say, the cure for cancer or cloned a human being, be very, very skeptical. The word "breakthrough" is often a clue, as there are few true breakthroughs in science.
Does the source of information have an intentional bias? Conservapedia, for example, admits up front that they are written from a conservative viewpoint, and so it should be no surprise that they call climate change "mostly a natural phenomenon."
Is it a minority point of view? I'm not saying that the majority is always right, but if someone makes a claim that goes against the majority of scientists or doctors, that claim deserves more skepticism and investigation.
Is the story almost too good to be true? Urban legends persist because they capture our imaginations and contain just enough (or possibly too many) details to sound true. And they often come to us directly from people we trust (who got them from people they trust, who got them from people they trust). Check out suspicious stories at Snopes.com or other sites that fact-check tales of alligators in the sewer system or chihuahuas that are really rats. Even if a story is true, remember that the plural of anecdote is not data. Some smokers live to be 100 years old, but it's still the case that smoking kills.
Is the source of information a TV or movie star? For reasons I will never understand, some people take their medical advice from actors like Jenny McCarthy. Dateline even gave over an entire hour to the crazy cancer theories of Suzanne Somers. But a general rule should be that you shouldn't trust information coming from someone who deals in fiction for their day job.
A note on Wikipedia: The problem with Wikipedia is that you can't answer many of these questions when reading the crowd-sourced Web site. But while I would never take medical advice from here, I do often use it to find other trusted sources, thanks to the footnotes.
What sources do you trust most for your science and medical information?