Date: Sun, 25 Sep 2005 12:51:30 +0200
ReplyTo: Marta GarcíaGranero
<biostatistics@terra.es>
Sender: "SPSSX(r) Discussion" <SPSSXL@LISTSERV.UGA.EDU>
From: Marta GarcíaGranero
<biostatistics@terra.es>
Organization: Asesoría Bioestadística
Subject: Re: Standard Error of an Fstatistic
InReplyTo: <0741DA624F60AE43A659DD2264AA4A65FDA7E5@ucsur8.ucsur.nt.pitt.edu>
ContentType: text/plain; charset=ISO88591
Hi Bozena,
I think you have a slightly wrong idea of what a standard error is
used for. We can talk about the standard error of a certain statistic
(used like estimators of the corresponding parameters in their
populations of origin), like the mean, a difference of means (like in
the case I answered before), a percentage, a difference in
percentages, an Odds Ratio, a Relative Risk... They reflect the
precision of your measure, and are used both for testing and computing
confidence intervals. You don't normally talk about standard error of
a F, Chisquare, Student's t statistic... they are used just to obtain
the pvalue for a given test.
What do you mean by the standard error of the Fstatistic for
interaction?. This Fvalue is used to obtain a test pvalue, only for
that.
ZB> Close to the topic, can someone tell me the formula for the
ZB> standard error for the Fstatistic for interaction? I ran a RM
ZB> Ancova using GLM and I am not sure how to calculate the standard
ZB> error for the Fvalue based on my output.
HTH
Marta
