I recently wrote an article for a community newspaper attempting to explain to scientifically naive readers why testimonial “evidence” is unreliable; unfortunately, they decided not to print it. I considered using it here, but I thought it was too elementary for this audience. I have changed my mind and I am offering it below (with apologies to the majority of our readers), because it seems a few of our readers still don’t “get” why we have to use rigorous science to evaluate claims. People can be fooled, folks. All people. That includes me and it includes you. Richard Feynman said
The first principle is that you must not fool yourself–and you are the easiest person to fool.
Science is the only way to correct for our errors of perception and of attribution. It is the only way to make sure we are not fooling ourselves. Either Science-Based Medicine has not done a good job of explaining these vital facts, or some of our readers are unable or unwilling to understand our explanations.
Our commenters still frequently offer testimonials about how some CAM method “really worked for me.” They fail to understand that they have no basis for claiming that it “worked.” All they can really claim is that they observed an improvement following the treatment. That could indicate a real effect or it could indicate an inaccurate observation or it could indicate a post hoc ergo propter hoc error, a false assumption that temporal correlation meant causation. Such observations are only a starting point: we need to do science to find out what the observations mean. (more…)