Re: [Paddlewise] Rudder redux

> On 7/3/07, Nick Schade <nick_at_guillemot-kayaks.com> wrote:
>
>> I guess I don't see any statistics here.
>
>
> Caffyn took his average daily mileage before rudder installation and
> compared it with his average daily mileage after rudder installation and
> published that figure. That is a statstical analysis; however rudimentary

He essentially divided one long distance by a long time (e.g 1000 miles in
25 days or whatever) and compared it to another long distance divided by
another long time in a different place. While these are averages, they
aren't statistics.

Statistics require multiple samples and they should be interspersed with
each other.

>
>> He has not done anything to raise it above the level of
>> anecdote.
>
>
> So you don't think that the daily records of mileages on a trip of that
> length amounts to any more than "anecdotal"?
>
> And how would you "raise" data to something above anecdotal? I have the
> feeling that we are talking at cross-purposes here. Anecdotal data would
> not
> be a series of mileage entries. It would be something on the order of, "I
> must've paddled 100 miles that day."
>
No, a series of consecutive days doing the same thing are just one sample.
Precise data from one incident is still anecdotal. Caffyn would have to
have, at the very least, randomly alternated between rudder and non-rudder
a couple times during his trip to produce statistical results. Instead he
did one thing on the first part of his trip and something different on the
later part.

> The fact that Caffyn is an "expert" makes it an anecdote
>> worth paying attention to, but his conclusions are still capable
>> being mistaken.
>
>
> Well, aren't all conclusions capable of being mistaken? And, again, why
> would his records be anecdotal?

Because, despite the fact that the data was taken over multiple days it
amounts to just one incident.

Nick
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