I regularly receive emails from friends who are concerned because they had received an email informing them of a new type of crime, a grievous social injustice, a rampant computer virus, etc. Perhaps the more excited or agitated something makes us, the more we want to believe it and spread the word (a riff on Hitler’s “Big Lie” theory). Many have cautioned against the “news” relayed by bloggers, and to rely upon the better credibility of authoritative sources.
That being said, authoritative sources from the New York Times’s Judith Miller to the CNBC’s financial expert Jim Cramer have had their credibility issues. Newspapers and television, with their financial stake in attracting readers thrive on inflating the scandal factor of the events around them.
And now the mushrooming growth of social networks where everyone tweets, blogs and provides status updates, grasping for something to say has to be added to the mix of what to believe and what to cast aside as talk for the sake of networking. Maybe the same drive to network socially drives us to have our friends and colleagues join us in our cause(s). It’s not just misery that loves company, but joy and indignation too.
Yesterday, when I was pulling together some statistics for the follow-up discussion to my blog post on bicycle helmets and safety, I was taken aback by a statement on the statistics page of the Bicycle Helmet Safety Institute. They caveated one of their statistics sets by saying:
“We don’t know where the numbers in the bullet point above and the chart below originated. The data to make that determination is not usually collected in the field.”
Overall it was an excellent page of statistics, and I applaud the BHSI for noting that they don’t know where the data came from, but it also meant that I had to look elsewhere for a source that could stand by its data.
The credibility others give to a source higher on the status hierarchy can’t be denied. Fifteen years or so ago, when I was in a role that had me in a relatively low status role collecting and assessing information in order to make determinations that would have a permanent legal impact, my practice was to collaborate with other agencies in pooling the raw data and assessments, and then make a case for Washington’s concurrence. In the initial analysis phase, I had to be careful in reviewing information from other agencies because occasionally I would recognize my own work there, simply recycled, but now bearing the authority of another, often higher status office. I had to be carefully internally not to create a circular argument in which my own conclusions were used to justify themselves. But, in presenting a case to others, it was helpful to present the assessment as having come from the higher status office.
When you need to make a decision based on accurate information, it may not be the prestige of the analyst that’s important, but an ability to identify the source of the information and assess the analytical methods. I guess that’s what transparency is about.
For more helmet and cycling statistics, I’ll through in a plug for my colleagues at NHTSA’s bicycle safety program [ka-ching!]
Thanks Darren, Excellent tie-in, particularly with regards to authority vs transparency and risk management. Let’s say I want to make an informed decision about managing the risk of riding a bicycle. Going to the NHTSA site, I find this document on Traffic Safety Facts which looks promising. Looking through it though, I see statistics on the number of fatalities, organized by age, gender, state, etc. but no statistics that could help guide me in managing my own risk. That being said, there is the advice at the end of the brochure saying:
“All bicyclists should wear properly fitted bicycle helmets every time they ride. A helmet is the single most effective way to prevent head injury resulting from a bicycle crash.”
All right, this is the risk management advice I was looking for, but where is the data (other than the authority of the NHTSA) to support it?
Figuring that there must be some data on the site, I find that there is a “Fatality Analysis Reporting System” which looks like it could have real potential; but, drilling down to the data on bicyclists or “pedalcyclists” I find a wealth of additional data on age, time of day, type of vehicle and where it hit, and a host of other factors such as:
Riding, playing, working, etc. in roadway
Failure to yield right of way
Improper crossing of roadway or intersection
Operating without required equipment
Erratic, reckless, careless, or negligent operation
Not Visible
Failure to keep in proper lane or running off road
Making improper turn
Inattentive (Talking, Eating, etc.)
Driving on wrong side of road
Failing to have lights on when required
Improper entry to or exit from trafficway
Improper lane changing
Other factors
None Reported
Unknown
but nothing amidst all this data to support the claim about bicycle helmets.
As a citizen that wants to trust but verify, where’s the supporting data?
Your point is true, that the statement is unsupported in that document. It’s one of those seemingly obvious assertions that really deserves substantiation. But if you are looking to manage your own risk, there are actionable things you could learn about the proximate causes of bike accidents (be extra careful ‘pedalcycling’ in Florida, if you’re a male 10-15, if it’s between 5-9PM, etc).
The biggest question I have in that particular document, though, is the injury data. As you might infer from the rounded numbers, they are estimates. There’s no statement about the basis of the estimates, other than it’s based on something called the General Estimates System. And it’s widely believed (feel free to call me out on that totally unsupported assertion) that bicycle injuries are highly underreported, making the use of an estimate that much more important in judging the credibility of the findings.
Anyway, I’m off to ‘pedalcycle’ home, have a great weekend!
Thanks again. And I hope that you’re taking the appropriate precautions of staying out of Florida during the danger hours. And avoid that whole male 10-15 thing altogether.
I remember the introduction to my course on statistics years ago. The instructor noted that statistics indicated that eating ice cream caused fires. After all, whenever there was an increase in the sale of ice cream there was a concurrent increase in fires.
Factoring in that both occured during the summer might alter the analysis, but that was optional.
I will keep my helmet on, stay on backroads, and watch for cars and dogs. It’s tough biking.
While I don’t know where the following factoid came from, of the 7% of cyclists who throw their helmets at dogs when attacked, 87% continue on their journey safety, highlight the dual-use value of a bicycle helmet.