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OT: Word to the wise - Re: Visualizing where to draw the standard
deviation line
Posted:
Jun 15, 2012 1:53 PM
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On Jun 15, 10:23 am, Kaba <k...@nowhere.com> wrote:
> 15.6.2012 19:01, Onion Knight kirjoitti:
>
> > Do you know much about linear trendlines? The same debate included the
> > drawing of those in Excel. The same person who spoke of the standard
> > deviation also showed how to make a linear trendline,
> >http://tmp.gallopinginsanity.com/LinearTrendLineCreation.mov
>
> > Others in the same group insisted he was missing steps but if you look
> > at the Microsoft site it offers instructions and it seems his process
> > is just fine. What steps if any did he skip? Would love to get some
> > other input from people who are not involved.
>
> I gather there are two questions here:
>
> 1) Is the trendline approriately fitted to that data?
>
> 2) Is the trendline useful in some way?
These two are being totally dishonest (Snit and Onion Knight). This
ruckus came from Snit's initial claim that there was a "correlation"
between UI improvements in Linux and an "upward tick" in Linux' market
share. Snit failed to support this allegation when another poster, cc,
asked Snit to support the "correlation", notably, Snit replied:
"The correlation fits with my prediction.
Snit's "prediction" and his allegation of a correlation were the
reason that the topic of a trend line even came up. As you can see if
you bother to look at it, given the data used, Snit stood no chance of
supporting the correlation he claimed.
> Answering question 1, there are many ways to a line to data. These go
> under the umbrella term of linear regression:
>
> http://en.wikipedia.org/wiki/Linear_regression
>
> It is possible to choose it differently how to measure the goodness of a
> fit. No doubt in the video the lines are fitted using ordinary least
> squares. Least absolute deviations, for example, would give something
> similar.
>
> Answering question 2, no. The trendline is attempting to build a model
> for the data. Models are created to summarize and to predict the future
> (think of physics). In this case the line has no summarization value,
> since _all_ of the data can be seen at glance. Since there is so small
> amount of data, and so much fluctuation, the line probably does not have
> any prediction value either.
Agreed, which is why I previously told Snit he should be questioning
the use of a line at all... but the argument was really a dick
measuring contest based on which line was a better fit and Snit's line
lost.
Onion Kinight is a Snit sock puppet or shill who has never posted to
usenet prior to this debate... Snit has done things like this for
years. He is one of the biggest liars you'll probably ever see on
usenet, there are scores and scores of posters who have all labeled
him a liar, troll or worse because of his online antics:
https://groups.google.com/group/comp.os.linux.advocacy/msg/6e8fd0b61d327d78
My suggestion: Don't get sucked into his BS.
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