This week a PSA was released by Sandy Hook Promise which is a graphic and disturbing effort to draw attention to behavior which might indicate that someone is at-risk for engaging in violence with a gun. The purpose is to build awareness about gun violence prevention through collaboration, training and group discussions in schools and other public venues. The group claims to have trained more than 1 million educators, parents, community leaders and students in their “Know The Signs” program, and they must be doing something right because Gun-nut Nation has lost no time in warning their folks that the project is nothing more than another attempt to take away everyone’s guns.

One part of their website which drew my attention is a downloadable factsheet on gun violence with data divided into daily and annual numbers based on an average for the years 2003 to 2013. Thanks to our friends at the Gun Violence Archive, some of the gun violence numbers, which come from the CDC, have been shown to be pretty far off, particularly true for accidental shooting deaths and even moreso for the number of individuals shot by cops. But the number I found most interesting was the topmost category of the Gun Facts sheet, something called “Acts of Gun Violence” which is a category of gun violence that I have never seen before. And the number, which is an average of 549,380 each year between 2003 and 2013, is so astonishingly large that I decided to look further and try to figure it out.

The number comes from a DOJ – Bureau of Justice Statistics publication, “Firearm Violence, 1993-2011,” used by the Sandy Hook people to come up with their half-million average gun violence figure by averaging yearly numbers from 2003 to 2011. What pushes the overall average up to just slightly under 550,000 is a big jump in one year- 627,200 shootings in 2006 – moving the annual average to what otherwise would have been around 475,000 gun assaults each year. I’m not saying that 550,000 criminal gun assaults is something to sneeze at; I’m saying that the ‘annual average’ of just under 550,000 does not accurately represent these stats.

The number that DOJ calls ‘criminal firearm violence’ and Sandy Hook calls ‘acts of gun violence’ comes from the annual survey of criminal victimization known as the National Crime Victimization Survey or NCVS. This annual survey is mandated by Congress because the only other national crime data is generated by the FBI, and their numbers are based on how many people are arrested or crimes are reported, both of which, as we know, are far below the actual number of crimes. The NCVS numbers are collected from interviews with more than 160,000 people each year and I can tell you from personal experience that the NCVS analysts know how to crunch numbers and crunch them very well.

There’s only one little problem with the NCVS numbers on gun violence. They are based on nothing more than a good guess. Because if you take the trouble to drill down to the actual survey questions from which this data is derived, you discover that respondents are asked whether they were attacked with a knife or a gun but they are not asked to specify which was which. And since the FBI tells us that for every ten reported assaults, six involve a gun and four involve a knife, I guess this is how the NCVS come up with their number on gun crimes which then are used by BJS which then end up in the factsheet published by Sandy Hook.

Now you would think that for something as serious and costly as gun injuries that we would try to establish some numbers that are even reasonably accurate, never mind simply meeting the test of good, common sense. But neither accuracy nor common sense will define how government will collect or use data over the next four years. If they bother with data at all.