Re: I crash into religion
In article <iM*Zgxhr@news.chiark.greenend.org.uk>,
damerell@chiark.greenend.org.uk says...
> Quoting Espressopithecus (Java Man) <rickk@letterectomyTELUS.net>:
> >As I've said in other posts, feel free to make your own decisions about
> >which gross population level statistics to apply to your particular
> >situation, and which not. I'm not trying to make a case for everyone
> >disregarding all statistics -- I'm trying to make a case for making good
> >decisions in the absence of statistics that bear directly on the
> >question at hand.
>
> Now, how might we know if that decision is good?
Without additional data, we won't, as with you and wine drinking, and as
with those athletes whose so-called "risky" BMIs were, by the best
population data available, put them at higher risk of cardiovascular
disease. Of course, that was before further studies showed that fit,
muscular men with high BMIs were NOT at increased risk despite the
overall population findings. But you would have them . . . do what? .
.. . stop exercising until their BMIs were in line with the best
available whole population evidence?
>
> If the population statistics show zero net effect for helmets, but your
> deduction is that nevertheless you are in a group that gets a positive
> effect, there are three questions to answer.
>
> 1) What's the group that gets a negative effect?
You've already addressed that.
---------------
"Well, quite. I don't want to talk about off-roaders, really; I don't
think many of the large-scale studies pertain to off-road riding, I
don't think it can tell us much about on-road riding, and while I'd
oppose compulsion for off-roaders I think the benefits of foam hats
there may well be positive."
---------------
If off-roaders aren't included in the population stats, why does there
have to be a group that "gets a negative effect"?
>
> 2) Given the idea we have of the effects that cause helmets to have a net
> zero effect - rotational versus direct impacts, etc - do those seem like
> the sort of thing that one type of riding might be particularly prone to?
I don't know, but I agree with your assessment above -- "for off-roaders
I think the benefits of foam hats there may well be positive".
>
> 3) Given that everyone who makes this deduction imagines they are in a
> group that gets a positive effect, they can't all be right. What's special
> about you?
>
What's special about me? Nothing, but I do try to keep up.
Rick
