Date:         Wed, 9 Oct 2002 15:37:46 -0700
Reply-To:     Alison Neustrom <alison@blueprintrd.com>
Sender:       "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>
From:         Alison Neustrom <alison@blueprintrd.com>
Subject:      Re: Sample vs Population
In-Reply-To:  <3DA47A51.4030901@citrus.ucr.edu>
Content-type: text/plain; charset=Windows-1252

What would you say if you had 80% of a non-random sample of a population (I
sent them to everyone but only got back 80%)? Would you consider that a
sample or a population?


-----Original Message-----
From: SPSSX(r) Discussion [mailto:SPSSX-L@LISTSERV.UGA.EDU]On Behalf Of
Jelani Mandara
Sent: Wednesday, October 09, 2002 11:50 AM
To: SPSSX-L@LISTSERV.UGA.EDU
Subject: Re: Sample vs Population


Fink, Steven wrote:

>Recently, I've been asked by several analysts about analyzing populations,
that is, data not from a sample.
>
>The purpose of a statistical test is to make estimates about the
population.  If my data set IS the population, are significant tests
appropriate?
>
>
>
No.  Descriptives and Effect Sizes are still relevant, but not
inferential stats.

>
>
>What about if my response rate (survey/unit) is low, say 20%.  For example,
I sent surveys to everyone in the population, but only received 20% of
responses.  Does this change your answer to the first question?
>
>
>
>

Then you only have a (probably nonrandom) sample of the population.  The
logic of inferential stats applies.

>Thanks
>
>
>
>Steve
>
>
>

--
Jelani Mandara
Assistant Professor
Human Development and Social Policy
Northwestern University
2120 Campus Drive
Evanston, Il 60208

Office Phone: (847)491-3122
Web Page: http://www.sesp.northwestern.edu/people/sp/j_mandara.html