## Re: [ARRL-LOTW] Duplicates

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• Just an observation on the data. We only get a snapshot of data provided by the ARRL website we do not have all the data to do a full analysis. Thus with
Message 1 of 147 , Feb 23, 2013
Just an observation on the data.

We only get a snapshot of data provided by the ARRL website we do not have all the data to do a full analysis.   Thus with this snapshot is not the only reasonable calculation that we can do is for COV?

COV = Coefficient of Variation

Just wondering as I only see the dribble of data shown at the website.

~73
Don
KD8NNU
-.- -.. ---.. -. -. ..-

Sent: Thursday, February 21, 2013 8:18 PM
Subject: Re: [ARRL-LOTW] Duplicates

Joe,
I hate to tell you this, but the definitions as stated below are exactly
backwards.

The MEDIAN value is that value for which the number of values below it
equals the number of values above it.

The MEAN of a dataset is the sum of all the values divided by the number
of values; this is commonly called the average value.

For a symmetrical distribution the median and the mean are identical.
In the case of LOTW uploads, with many small and fewer large uploads,
the median will certainly be smaller than the mean.

I am sure you know this, but it came out backwards in your response to
Keith.

73
Pete Jordahl, K5GM
(and Keith, yes I am qualified to make the above statements, having a
Ph.D. in Astronomy)

On Thu, Feb 21, 2013, at 06:22 PM, Joe Subich, W4TV wrote:

>
> > can you tell me what the difference is between the
mean and the
> > median? also, what is the standard deviation?
>
> The median is also known as the average ... the mean is the point
that
> divides the population in half (half larger, half smaller).
Standard
> Deviation is a measure of the randomness or spread of the data.
Lower
> standard deviations indicate the data is more tightly clustered
> the mean while larger standard deviations indicate the
distribution is
textbooks.
>
> > All your statistics only apply to normally
distributed populations,
> > and not to skewed data, like your
set.
>
> Not true. Statistics are applicable to "single tailed"
distributions
> just like "normal" ("bell curve") or rectangular
distributions as long
sizes and confidence
> levels. Single tailed distributions are often
encountered where the
> property being sampled can not go below zero (no
logs/QSOs) but has no
> practical upper bound.
>
> > The
data about log submissions in the amateur world is highly skewed; I
> >
cannot rigorously prove this, but logical examination is appropriate.
>
> There is no need to "prove" that .. it's assumed in analysis of
this
> kind of data and one reason for the larger sample size.
>
> Again, if one knows the population has a single tail, uses
appropriate
> sample sizes and applies the "single tail" formulas, the
analysis is
> just as valid as "normal" or "rectangular" (two tailed)
populations.
>
> 73,
>
> ... Joe, W4TV
>
>

• I run ACLog... When you hit the ALL SINCE button, change the date to be something about a week prior to the LoTW failure... I believe , ACLog got very
Message 147 of 147 , Aug 24, 2014
I run ACLog... When you hit the "ALL SINCE" button, change the date to
be something about a week prior to the LoTW failure...

I "believe", ACLog got very confused as a result of the fail mode of
LoTW. That corrected a very similar problem for me.
--
Thanks and 73's,
For equipment, and software setups and reviews see:
www.nk7z.net
for MixW support see;
http://groups.yahoo.com/neo/groups/mixw/info
for Dopplergram information see:
http://groups.yahoo.com/neo/groups/dopplergram/info
for MM-SSTV see:
http://groups.yahoo.com/neo/groups/MM-SSTV/info

On Sun, 2014-08-24 at 09:05 -0700, reillyjf@... [ARRL-LOTW]
wrote:
>
>
> Thanks for the suggestion. I did a complete download, and beat the
> number of duplicates down from 275 to 30. No exactly sure why the
> N3FJP ACL is missing this information.
> - 73, John, N0TA
>
>
>
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