Matt Seaton on H*lm*ts

bugbear bugbear@trim_papermule.co.uk_trim said:

http://www.guardian.co.uk/g2/story/0,,2102447,00.html

I think he's getting the message...

Maybe he's been reading the recent debate in the Times.

-Alex

Quoted message said:

http://www.guardian.co.uk/g2/story/0,,2102447,00.html

I think he's getting the message...

No mention that cycling is pretty safe compared to walking :-/

bugbear said:

http://www.guardian.co.uk/g2/story/0,,2102447,00.html
I think he's getting the message...

I appreciate the sentiment, but I think it would be a shame
if cyclists were to come to depend on Ian Walker's study as
their main line of argument against helmet compulsion.

First, Walker's is only one study and may be mistaken. (There
may be confounding factors just as big as in some of the studies
wheeled out by the "other side" of the argument, e.g., Thompson,
Rivara & Thompson 1989.)

Second, close overtaking (as frightening as it can sometimes be)
is not the main source of danger to cyclists (so the argument is
weak: it's logically possible -- even if we doubt it in practice
-- that the additional danger from close overtaking is more than
balanced by extra safety in other types of collision).

Finally, depending on arguments that cycle helmets are
ineffective is a hostage to fortune. If they are even a little
bit effective, at least in some types of collision, then we
appear to have been refuted. Or if new designs of helmet are
produced that lack some of the disadvantages of the current
models it will be reasonable for helmet advocates to ask why we
won't wear *these* designs?

So I think we ought to be more careful about sticking to solid
arguments based on our *freedom* to accept small risks without
officious interference, and on the *unfairness* of being
required to wear helmets when pedestrians and motorists (who
accept similar risks of head injury) are not.

--
Gareth Rees

<gareth.rees wrote.

Quoted message said:

Finally, depending on arguments that cycle helmets are
ineffective is a hostage to fortune. If they are even a little
bit effective, at least in some types of collision, then we
appear to have been refuted. Or if new designs of helmet are
produced that lack some of the disadvantages of the current
models it will be reasonable for helmet advocates to ask why we
won't wear *these* designs?

So I think we ought to be more careful about sticking to solid
arguments based on our *freedom* to accept small risks without
officious interference, and on the *unfairness* of being
required to wear helmets when pedestrians and motorists (who
accept similar risks of head injury) are not.

--
Gareth Rees

For me, risk homeostasis is the most convincing theory explaining why
helmets don't work, and the most cogent argument against compulsion.

Mike Sales

[email hidden] wrote on 14/06/2007 18:06 +0100:

Quoted message said:

I appreciate the sentiment, but I think it would be a shame
if cyclists were to come to depend on Ian Walker's study as
their main line of argument against helmet compulsion.

It may be but it mirrors exactly my anecdotal experience when I stopped
wearing a helmet that was posted here ages before Ian Walker's study.
Given he is a sometimes visitor here in the past I even like to think my
posts might have given him the idea.

--
Tony

"The most savage controversies are those about matters as to which there
is no good evidence either way."
- Bertrand Russell

Mike Sales said:

For me, risk homeostasis is the most convincing theory explaining why
helmets don't work, and the most cogent argument against compulsion.

No, the most cogent argument against helmet compulsion is we've
actually *seen* what happens when it is done, and that it doesn't
help.

Solid empirical data trumps theory, and we've got the solid
empirical data.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

Quoted message said:

For me, risk homeostasis is the most convincing theory explaining why
helmets don't work, and the most cogent argument against compulsion.

Wot Pete said, plus I think the massive drop in cycling is the main reason
for the rise in injury rates - it's well established that more cyclists =
safer for individuals (see London for an example), so a drop in their
number will have the reverse effect.

Quoted message said:

bugbear said:

http://www.guardian.co.uk/g2/story/0,,2102447,00.html
I think he's getting the message...

Quoted message said:

I appreciate the sentiment, but I think it would be a shame
if cyclists were to come to depend on Ian Walker's study as
their main line of argument against helmet compulsion.

[snip v sensible stuff]

Quoted message said:

So I think we ought to be more careful about sticking to solid
arguments based on our *freedom* to accept small risks without
officious interference, and on the *unfairness* of being
required to wear helmets when pedestrians and motorists (who
accept similar risks of head injury) are not.

Very well said.

m.

Tony Raven said:

it mirrors exactly my anecdotal experience when I stopped
wearing a helmet that was posted here ages before Ian Walker's
study. Given he is a sometimes visitor here in the past I
even like to think my posts might have given him the idea.

I don't have any particular doubts about the Walker study; it
seems a plausible enough phenomenon. But coming to rely on it
as our main argument against compulsion would be risky. Suppose
a new study showed that mounting a reflective arm on your bike
caused motorists to return to safer passing distances. Then I
suspect that compulsion advocates would start to demand that we
wear helmets *and* mount reflective arms. So I think this is a
bit of a distraction from the real issues.

--
Gareth Rees

Quoted message said:

Tony Raven said:

it mirrors exactly my anecdotal experience when I stopped
wearing a helmet that was posted here ages before Ian Walker's
study. Given he is a sometimes visitor here in the past I
even like to think my posts might have given him the idea.

I don't have any particular doubts about the Walker study; it
seems a plausible enough phenomenon. But coming to rely on it
as our main argument against compulsion would be risky. Suppose
a new study showed that mounting a reflective arm on your bike
caused motorists to return to safer passing distances. Then I
suspect that compulsion advocates would start to demand that we
wear helmets *and* mount reflective arms. So I think this is a
bit of a distraction from the real issues.

Yes, I agree. While Walker's research looks okay as a start point it
certainly isn't a robust or big enough basket to have /all/ of one's
eggs in.

If you want to know what helmets actually do look at what they've
actually done.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

Peter Clinch' wrote Mike Sales said:

Quoted message said:

For me, risk homeostasis is the most convincing theory explaining why
helmets don't work, and the most cogent argument against compulsion.

No, the most cogent argument against helmet compulsion is we've actually
*seen* what happens when it is done, and that it doesn't help.

Solid empirical data trumps theory, and we've got the solid empirical
data.

Pete.
--

You are right up to a point. But data without a hypothesis is less useful,
and is easier to dismiss as an abberation caused by failings in data
collection and method. As we see, pro MHLs are able to dispute that the data
is solid and empirical. Without a convincing theory it is possible, as
Gareth Rees writes, to argue that a better helmet, or correct wearing or
some other change would make helmets effective.
I think that risk homeostasis is a useful account of what is wrong with
"road safety". Seat belts increase the danger to pedestrians and cyclists,
but are counted as a safety measure by the "road safety professionals".
Ignorance of risk homeostasis is behind many of the ways in which authority
tries to save us from ourselves, and in fact makes the road more hazardous
for the vulnerable.
Data and theory are not in opposition, one does not trump the other, they
should work together.

Mike Sales

Mike Sales wrote on 15/06/2007 15:55 +0100:

Quoted message said:

Peter Clinch' wrote Mike Sales said:

Solid empirical data trumps theory, and we've got the solid empirical
data.

Quoted message said:

Data and theory are not in opposition, one does not trump the other, they
should work together.

Solid empirical data always trumps theory. A theory can be disproved by
a single piece of solid empirical data but solid empirical data cannot
be disproved by any number of theories.

--
Tony

"The most savage controversies are those about matters as to which there
is no good evidence either way."
- Bertrand Russell

Mike Sales said:

You are right up to a point. But data without a hypothesis is less useful,
and is easier to dismiss as an abberation caused by failings in data
collection and method.

While that is so, reproducible empirical data is less prone to such
criticism. The various data looks pretty consistent so far.

Quoted message said:

As we see, pro MHLs are able to dispute that the data
is solid and empirical. Without a convincing theory it is possible, as
Gareth Rees writes, to argue that a better helmet, or correct wearing or
some other change would make helmets effective.

Though to be frank, seeing as we're dealing with Belief here (note
the capitalisation) then you're *never* going to convince these
people of anything. You might as well try and argue with the rabid
"every word in the Bible is literally true" crowd that Creationsim
is ridiculous: they know the answer, and yours isn't it. So any
theory you have will not be convincing.

Quoted message said:

I think that risk homeostasis is a useful account of what is wrong with
"road safety". Seat belts increase the danger to pedestrians and cyclists,
but are counted as a safety measure by the "road safety professionals".
Ignorance of risk homeostasis is behind many of the ways in which authority
tries to save us from ourselves, and in fact makes the road more hazardous
for the vulnerable.

All true, but only part of the story. There's more to it than just
risk compensation, I think, so concentrating on one possible casue
won't get you too far.

Quoted message said:

Data and theory are not in opposition, one does not trump the other, they
should work together.

They should, but we're not dealing with universally highly educated
and numerate people, we're dealing with people who are open to
emotional appeal, first impressions and you need to cut to the
chase. I think "this is what has happened before, this is almost
certainly what will happen again" is better at cutting to the chase
than "here is a possible theory on why we think helmets may not
work" acompanied by some arm waving. Furthermore, I am quite sure,
regrettably, that the answer to risk homeostasis will be "we just
need better helmets". Yes, of /course/ that *utterly* misses the
point, but look at the likes of BeHIT and their track record of
intellectual rigour.

Theory and practise should work together, but people knew that
apples would fall down out of trees a /long/ time before there was
any sort of gravity theory to explain why.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

On Fri, 15 Jun 2007 20:11:58 +0100,

Tony Raven said:

Mike Sales wrote on 15/06/2007 15:55 +0100:

Quoted message said:

Peter Clinch' wrote Mike Sales said:

Solid empirical data trumps theory, and we've got the solid empirical
data.

Quoted message said:

Data and theory are not in opposition, one does not trump the other, they
should work together.

Solid empirical data always trumps theory. A theory can be disproved by
a single piece of solid empirical data but solid empirical data cannot

^^^^^

Quoted message said:

be disproved by any number of theories.

The word solid being key. It is not at all uncommon for systemic or
systematic errors to be discovered only because the observed results are
so remote from the theory. (This is particularly true in the
undergraduate laboratory, the C candidates will report what they find,
the B candidates will report what was expected, and the A candidates
will report what they find and then explain why it differs from the
results the B candidates got ;-)

The one that immediately comes to mind is satellite measurement of
stratospheric temperature. (Of course there is still some dispute about
this)

Tim.

ISTR Isaac Asimov writing about how he plotted the data from an
experiment, drew the expected curve through the points and then labeled
it "Shotgun curve".

--
God said, "div D = rho, div B = 0, curl E = - @B/@t, curl H = J + @D/@t,"
and there was light.

http://tjw.hn.org/ http://www.locofungus.btinternet.co.uk/

Tim Woodall said:

ISTR Isaac Asimov writing about how he plotted the data from an
experiment, drew the expected curve through the points and then labeled
it "Shotgun curve".

Doing my labs in 1st year physics at uni we were told a definition
of a 1st year physics undergrad: "someone who can draw a straight
line through /any/ set of points".

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

Absolutely. All else is muddle, in which They do their ungodly work (such
as, witness thread further up, banning quick release wheels). Bottom line:
whose life is it anyway? Educate me, inform me, make me aware of 'the facts'
as you see them by all means, but beyond that, so long as I'm not hurting
anyone else, mind your own damn business. And that applies to The
Authorities exactly as much as it does to anyone else.
"Marianne Promberger" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Quoted message said:

bugbear said:

http://www.guardian.co.uk/g2/story/0,,2102447,00.html
I think he's getting the message...

Quoted message said:

I appreciate the sentiment, but I think it would be a shame
if cyclists were to come to depend on Ian Walker's study as
their main line of argument against helmet compulsion.

[snip v sensible stuff]

Quoted message said:

So I think we ought to be more careful about sticking to solid
arguments based on our *freedom* to accept small risks without
officious interference, and on the *unfairness* of being
required to wear helmets when pedestrians and motorists (who
accept similar risks of head injury) are not.

Very well said.

m.

Another Guardian article today (front page of the 'Work' supplement)
by Emily Thornberry (an MP) will bring a smile to some faces. A big
cartoon picture of cyclists in normal clothing and only lycra-man
wearing a lid. She seems to have lifted most of the content from urc
(not that anyone's likely to complain :-).

-adrian

Adrian Godwin wrote on 16/06/2007 08:58 +0100:

Quoted message said:

Another Guardian article today (front page of the 'Work' supplement)
by Emily Thornberry (an MP) will bring a smile to some faces. A big
cartoon picture of cyclists in normal clothing and only lycra-man
wearing a lid. She seems to have lifted most of the content from urc
(not that anyone's likely to complain :-).

-adrian

http://environment.guardian.co.uk/travel/story/0,,2104219,00.html

--
Tony

"The most savage controversies are those about matters as to which there
is no good evidence either way."
- Bertrand Russell

In article <[email hidden]>, Tony Raven
[email hidden] says...

Quoted message said:

Adrian Godwin wrote on 16/06/2007 08:58 +0100:

Quoted message said:

Another Guardian article today (front page of the 'Work' supplement)
by Emily Thornberry (an MP) will bring a smile to some faces. A big
cartoon picture of cyclists in normal clothing and only lycra-man
wearing a lid. She seems to have lifted most of the content from urc
(not that anyone's likely to complain :-).

Apart perhaps from "You can't tackle hills without gears." :-)

Quoted message said:

http://environment.guardian.co.uk/travel/story/0,,2104219,00.html

No mention of skinny saddles vs. the dark side.