"Just the facts, ma'am." The signature line of Dragnet's hardened detective Sgt. Joe Friday seems straightforward. With all due respect to Friday, nothing could be further from the truth. Data can be twisted and turned and reshuffled. As the old saying goes, if you torture the data long enough, you can get it to confess to anything!
Doctors were performing routine cancer screenings and expensive coronary bypass surgery until they took another look at the statistics. Dr. David Eddy estimated that as few as 15 percent of all medical protocols are actually based on sound data. These are doctors; professionals trained to make rigorous decisions. Do the rest of us have the faintest hope of success?16
Look at the quality of your data. If you put garbage in, guess what you'll get out? If you don't have good information, you can't make good decisions, but often we make assumptions about the quality of our information that aren't justified. People actually do rely on the Internet for medical information when much of it is not worth the pixels it is glowing on.
Statistics and other data can be a valuable resource in making a decision. But always consider the source. Is there an ulterior motive in offering a rosy picture or a dark picture? Where can you go for unbiased information? Does it exist? Even data sources that are not shaped by some nefarious motive can be limited in some natural way that obscures the true picture. Consider the biases that are inherent in your sources of information. Then look elsewhere to get a fuller view. Remember that any gumshoe would tell you that you need to pound the pavement for information before you can track down a suspect.
If you don't have good information, you can't make good decisions.