On 1 Sep 2003 11:52:50 GMT, Brian Sandle
wrote:

In sci.agriculture Gordon Couger wrote:

"Torsten Brinch" wrote in message
...

On Sun, 31 Aug 2003 20:45:07 GMT, "Gordon Couger"
wrote:

If you can make that pig of a paper sing by making the statistics work
I will continue the discussion.

That's very kind of you. However don't you think it is about time
you coughed up some evidence for your claim that data that did not
agree with findings was discarded? How many times have you been
asked for that now. Five, seven times?

I have no idea what the effect of the discarded data did to the study did.
That's the point.

No you need to be quite good at the subject to deal properly with
outliers. I am thinking that sometimes people do not eliminate them when
they should be, and others do but don't acknowledge it.

Imagine you represent a conservative govt applying as little as possible
health funding to a village of 100 people of mainly low income, based on
whether they can pay for it themselves or not. When calculating the
average will you include the income of the one multi-millionaire in the
village? That would make the average income rather higher, so you can fund
less. But the other 99 people would have no ability to pay, consequently.
The place would become a real eyesore.

But that's not an outlier problem, Brian. Indeed, there's not much of
a statistical problem in it :-) You have sampled the whole population,
you know the income of each and every individual in it, you know their
average income. The average is the average. It is just not a very good
descriptor for what the politicians want to describe.

Then if you were looking for how much the village could potentially donate
to a cause would the high earner still be an outlier?

Yes. In that situation average income might be a more suitable
descriptor. But again, this is not an outlier problem. The high earner
is known to be part of the population studied, so the data point
representing his income can never be considered an outlier.

If you were recording times for a cross country race would you include
ones where runners had obviously taken a short cut or joined the race some
way through it because they were rather briefer than really possible?
(Memories of school cross-countries). Well you might if you were trying to
catch cheats, or runners mistaken about the route.

That's more like it. If you observe from the recorded racing times
that all racers completed the race within a time range of 3-7 hours,
except one racer -- who has been recorded as completing it in 7
minutes -- that does raise the question if the racing time of this
runner should not be consider an outlier.