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Archiver > GENEALOGY-DNA > 2011-02 > 1297192853


From: "Ken Nordtvedt" <>
Subject: Re: [DNA] variance quiz game
Date: Tue, 8 Feb 2011 12:20:53 -0700
References: <002701cbc7a9$8c29ef30$c2482dae@Ken1><001401cbc7c3$84afe060$8e0fa120$@com>


----- Original Message -----
From: "Sandy Paterson" <>
To: <>
Sent: Tuesday, February 08, 2011 12:08 PM
Subject: Re: [DNA] variance quiz game


> I'd say the first estimate is better simply because in the trivial (but
> surely common) case where they match 3/4, the second estimate gives an
> answer of zero which is clearly nonsense. [[ All estimators blow up in
> fractional size of sigma as generations go to zero, so that limit must be
> handled with care. But see below. ]]

[[ What if the answer depends on the age (mG) of the pair? In fact, that is
what i have found preliminarily. For young TMRCA the usual linear in
Variance estimator has the smaller sigma for the estimation, but for old
TMRCAs the latter quadratic in Variance estimator seems to have the smaller
sigma for the estimator.

Needless to say, I am checking the mathematics now that my driveway
snowplowing is done for the morning. This would be very interesting, if
true. KN ]]


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