Don't Lie to Make Friends

I'm not suggesting that any one of you would intentionally tell a lie. But sometimes we can mislead people with information that doesn't paint the whole picture. For example, a recent "study" published by the AIM Group calls Craigslist, "a cesspool of crime." Citing hundreds of crimes committed by people using the free, online classified site to connect with their victims.

In one year, from February 2010 to February 2011 they cataloged 330 crimes linked to Craigslist including 12 murders (10 of which were by the infamous Craigslist Killer). That's staggering and shocking. But that's where this publication leaves off. Not once in the entire study does it mention the number of ads on Craigslist or the number of users participating in the site.

Over the same time that those crimes were taking place, Craigslist had 56 million different people visit the site with half a billion page views. There are about 50 million new ads posted to the site each month (for a total of 600 million new ads a year). So the 330 crimes are out of millions of ads and people participating in the site. That's a crime to user rate of: 0.0006%. More than that is a crime to ad rate of: 0.000055%. Compare that to the lowest crime rate in any US city over 250,000 people (Plano, TX) which is 1.7%. You are 2,884 times more likely to be the victim of violent crime by living in the safest city in America than you are by participating on Craigslist.

So calling Craigslist "a cesspool of crime" is a bald faced lie based on half-truths and poorly constructed research. Do not blindly spout statistics to support your point without first checking the sources. Even if you don't intend to, you might end up lying to people and broken trust is very difficult to mend.

How do you use statistics well in your presentations? How do you protect the truth?