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Subject: Re: crafty speedup numbers

Author: Gian-Carlo Pascutto

Date: 09:00:25 05/07/04

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On May 07, 2004 at 04:42:55, martin fierz wrote:

>and
>immediately add the question why one set is 38 positions while the other is 39,
>and also add the comment that with a much larger testset you could easily
>resolve your borderline significance.

Sometimes two different parallel searches (or a serial and a parallel search)
give a totally different variation and score, which make calculating a speedup
rather senseless.

>meaning that you  must use the same
>set of positions to make comparisons. you should throw out that position #39
>for your 0 / non-0 comparision.

I could, but it will not change the results.

>one final remark: with the little data available, i cannot check whether the
>speedup numbers are normally distributed at all. the computation of sigmas and
>statistical significance however assumes a normal distribution. if this is not
>the case (and it isn't necessarily!), then these computations about statistical
>significance have no proper meaning any more. that's the reason i'd classify
>2.17 sigma as borderline - you can't be sure that your distribution allows you
>to make such conclusions.

It's quite reasonable to assume they do, especially if enough positions are run.
You can verify it and I would be highly surprised if you disproved a normal
distribution.

Btw. 2.17 sigma being "borderline" is a weird way of saying that there's more
than 95% significance :)

--
GCP



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