Re: Standard error of heritability.

# Re: Standard error of heritability.

```Dear Bruce,
ASREML does not do anything very smart.

First, the syntax should be
F phen 1 + 2*3.2899
H h2_bin 1 2

[the syntax you used actually adds 1 rather than 3.2899]

Lets say the component is .0318 with se .0370  [values from an example of mine]

ASREML calculates phen as 0.0318 + 3.2899 = 3.3217
with var  .0379^2  and covariance with component the same

It uses the expression in the manual [Section 6.2.2]
for the SE of h2

viz sqrt( (N/D)^2  V  [1/N^2  + 1/D^2 - 2/(ND)])
=   (.0318/3.3217) (.0379) (1/.0318 - 1/3.3217)
= 0.0113
In other words,  it is scaled by the heritability and by the size
of the genetic variance.

Maybe you can come up with a better estimate.

Best wishes

Arthur

> X-Authentication-Warning: lamb.chiswick.anprod.csiro.au: petidomo set sender
to asreml-owner@lamb.chiswick.anprod.csiro.au using -f
> From: bsouthey@iastate.edu
> To: Arthur Gilmour <gilmoua@ornsun.agric.nsw.gov.au>
> cc: asreml@chiswick.anprod.csiro.au
> Subject: Standard error of heritability.
> Mime-Version: 1.0
> Date: Mon, 06 Dec 1999 17:04:51 CST
>
> Hi,
> How does ASREML compute the associated standard errors for the heritability
> with a binomial distribution?
> Since the 'residual' variance is always known, is this due to the method of
> Schall?
>
> Thanks in advance,
> Bruce Southey
>
> .pin for the logit link:
>
> F phen 3.2899 + 1
> H h2_bin 1 2
>
> --
> Asreml mailinglist archive: http://www.chiswick.anprod.csiro.au/lists/asreml

<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
Arthur Gilmour PhD                  mailto:Arthur.Gilmour@agric.nsw.gov.au
Principal Research Scientist (Biometrics)            fax: <61> 2 6391 3899
NSW Agriculture                                           <61> 2 6391 3922
Orange Agricultural Institute             telephone work: <61> 2 6391 3815
Forest Rd, ORANGE, 2800, AUSTRALIA                  home: <61> 2 6362 0046

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