[pct-l] Probability of Disaster

[Yoshihiro Murakami]

Thanks Greg

The point I would like to say is that we are tend to underestimate the
danger. The experts tend to go into the difficult situations, then the
injury rate do not differ from the unexperienced hiker. The research
suggested that the basic pack weights were very different among the
long-distance hikers, and there was no evidence the lighter packs were
 safer than the heavy packs or the heavy packs were safer than the
lighter packs.

I would like to remain to this PCL member for a few years, although I
am a Japanese,  because many interesting and intelligent peoples
belongs to this list.

I had taken 25000 photos of the JMT in this summer, so I need more
times to select and upload to my blog.





2010/9/3 greg mushial <gmushial at gmdr.com>:
>>
>> Message: 1
>> Date: Thu, 2 Sep 2010 12:19:47 +0900
>> From: Yoshihiro Murakami <completewalker at gmail.com>
>> Subject: Re: [pct-l] Probability of Disaster
>> To: Diane Soini of Santa Barbara Hikes <diane at santabarbarahikes.com>
>> Cc: pct-l at backcountry.net
>> Message-ID:
>> <AANLkTiktF8q0vs3_+t3p5583w8pnMJuvwXSeT4ioJXRK at mail.gmail.com>
>> Content-Type: text/plain; charset=ISO-8859-1
>>
>> A few study was done.  Anderson et al.(2009, Wilderness and
>> Environmental Medicine, 20, 250-256), studied the 128 long distance
>> hikers who walked AT or PCT.
>>
>> Their basic pack weight were
>> 10-20   52 ( 34.9%)
>> 21-30   37( 30.1%)
>> >=31    34(27.6%)
>>
>> Footwear
>> Hiking boots   44( 34.9%)
>> Low-top hiking boots 27(21.4%)
>> Running shoes       48(38.1%)
>> Sandals                    7(5.6%)
>>
>> Increasing pack weight was associated with increasing the
>> paresthesias, but not with the musculoskeletal injuries.
>>
>> Footwear type was not associated with the injuries, simply because
>> heavy packs user wears heavy boots. So, when the heavy pack user wears
>> shoes, the danger of injury will appear.
>>
>> So, based of this article, the light weight backpacking  has a effect
>> of reducing the paresthesias, but no effect of reducing the injuries.
>>
>>
>> ---------------------
>>
>> Concerning the probability,
>>
>> if bad things happen at probability 0.1 ( assuming events are
>> independent as Jim and Jane said, when events are dependent, difficult
>> to analyze)
>>
>> Assuming
>> bad event1... 0.1
>> bad event2 ... 0.1
>> bad event3 ...0.1
>>
>> The probability of no occurrence of bad events is
>>
>> (1 -0.1 ) X (1 - 0.1 ) X ( 1 - 0.1 ) ..... --> 0.9 X 0.9 X 0.9 = 0.729
>>
>> Then the probability of bad events is
>>
>> 1 - 0.729 = 0.271
>>
>> The intuitive thinking of probability often misleading.
>
> Besides, a learned understanding of probability is a whole lot more useful
> in dealing with real life...  welcome back Yoshihiro - hope the trip was a
> good one [will you be posting pictures?? please ;-)   ]
>
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-- 
Sincerely
--------------- --------------------------------------
Hiro    ( Yoshihiro Murakami )
HP    http://psycho01.edu.u-toyama.ac.jp
Blogs http://completewalker.blogspot.com/
Photo http://picasaweb.google.co.jp/CompleteWalker/
Backpacking for 30 years in Japan
2009 JMT, the first America.
2010 JMT, the second America.
------------------------------------------------------