Date: Mon, 21 Aug 2006 13:05:17 -0300
Reply-To: Hector Maletta <email@example.com>
Sender: "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>
From: Hector Maletta <firstname.lastname@example.org>
Subject: Re: Relationship between Sets of Dependent and Independent
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You state your friend's goals in a very sketchy way, so it is very difficult
to give an opinion. For instance, how many variables are involved? 200 cases
may be way too few if the variables happen to be (even moderately) numerous.
Is he/she interested in bivariate or multivariate relations between these
variables? For instance, one may be interested in crossing pairs of
variables such as X BY Z BY sex, and see whether the association/correlation
of X and Z varies with sex, and this may be feasible with 200 cases (140
women, 60 men), only if one has, say, K variables there would be K*(K-1)/2
pairs of variables, which rapidly goes into the hundreds or the thousands as
K grows. For K=50, there are 1225 pairs of variables to consider. If one is
interested in models involving many variables, such as regression, the
number of possible models grows exponentially and, besides, the small number
of cases in the sample becomes rapidly a limitation.
Another consideration is whether your friend has any theory or conceptual
approach or problem-oriented goal when facing these data, or is just
exploring blindly around. What is he/she looking for? Just mining around for
any kind of non-random-looking patterns, like an astronomer searching for
signs of extra-terrestrial intelligence among random electromagnetic cosmic
noise, or like John Nash, he of the beautiful mind, parsing newspapers in
the worst of his madness? In a sample of 200 she/he may find many promising
patterns, but they may be nothing but sample flukes.
De: SPSSX(r) Discussion [mailto:SPSSX-L@LISTSERV.UGA.EDU] En nombre de Susan
Enviado el: Monday, August 21, 2006 10:44 AM
Asunto: Relationship between Sets of Dependent and Independent Variables
Dear Listserv members:
A colleague is interested in examining the relationship between two
sets of variables (dependent variables and independent variables).
Additionally she would like to investigate whether the relationship varies
between men and women. The total sample size is somewhat moderate (about
200 participants) with 70% being women. What might be a good approach to use
when analyze these data in light of the objectives? Any suggestions are