I m not a scientist is a familiar refrain among people asked to evaluate scientific claims they feel are beyond their ken. Most citizens learn about science from media coverage, and even the most conscientious reporters sometimes struggle to offer a clear, unbiased explanation to readers. Politicians, activists, business spokespersons, and religious leaders with their own agendas to pursue also influence the way science is reported and discussed. Meanwhile, anyone seeking factual information on climate change, vaccine safety, risk of terrorist attack, or other topics in the news must sift through an avalanche of bogus assertions and self-interested spin.