Date:         Tue, 8 Apr 2003 11:49:40 -0700
Reply-To:     Dale McLerran <stringplayer_2@YAHOO.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Dale McLerran <stringplayer_2@YAHOO.COM>
Subject:      Re: Statisticians (was S.O.S. (Save Our SAS))
In-Reply-To:  <se92d322.069@MAIL.NDRI.ORG>
Content-Type: text/plain; charset=us-ascii

--- Peter Flom <flom@NDRI.ORG> wrote:
> >>> "David L. Cassell" <cassell.david@EPAMAIL.EPA.GOV> 04/08/03
> 01:31PM
> >>> wrote
> <<<
>  As a statistician, it is part of my job description
> to cause as much trouble as possible.  :-)
> >>>
>
> LOL
>
> When I was getting my PhD in psychometrics, professors from clinical
> or
> developmental psych would complain about how unreasonable we stats
> types
> were.  Samples were too small. We wanted to see power analyses.  We
> kept
> talking about assumptions being violated......And we did things like
> point out that ANOVA and OLS regression are the same model.
>

Let's back up a bit further.  What is the population for which
you wish to make inference?  What is your sampling frame?  Does
your sampling frame represent the population on which you wish
to make inference?  How were samples drawn?  Oh, you used
convenience sampling?  Sorry, that does not represent any
specifiable population.  Come back with an experiment which
employs proper sampling methods!

Oh, so your sampling frame does represent the population of
interest and you have used some acceptable method of drawing
observations from the sampling frame.  You do have correlated
errors induced by your sampling.  Thus, you cannot use any of
the statistical techniques which you learned in Statistics 101.
Here, let me try to explain.  (Eyes glaze over - didn't even
understand Stat 101 all that well.  Just don't tell me any
more, please!)

We are a troublesome lot, for sure!

Dale

=====
---------------------------------------
Dale McLerran
Fred Hutchinson Cancer Research Center
mailto: dmclerra@fhcrc.org
Ph:  (206) 667-2926
Fax: (206) 667-5977
---------------------------------------

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