R friends,

Before coming to this post I did take a look at Rothman's book and Sklo's
book, but not very iluminating so far.

Recently I was challenged with a problem of causal diagrams.

A partner o mine came with a dataset with more then 1500 observations and
more then 1500 variables.

Trying to organize the ideas on how and what to explore we came to a point
where we were drawing causal diagrams such as:

A -------> B ------> Outcome
|          ^          ^
|          |          |
D -------> C ----------

Im not able to draw the diagram we came to, but it looks like it has at
least 3 stages and some variables may come into more then one stage
simultaneously. And also it seems that at least one variable is outside the
diagram and directly related to the outcome.

Looking at this diagram it does not seem reasonable to me the a multinomial
or a logitic regression may represent such an idea.

So my guess is that y = x1B1 + .... + xnBn may not reasonably represent the
diagram above.

At this point I thought that a neural network could work fine as one
theoretical argument often seen at the neural networks text is that it may
reasonably approximate any function.

So the question is: how to statistically test a diagram such as the above?

Also, looking forward for any comment and perhaps suggestions for further
reading on this topic.

Kind regards,

Dr. Pedro Emmanuel A. A. do Brasil
Curriculum Lattes:  http://lattes.cnpq.br/6597654894290806
Instituto de Pesquisa Clínica Evandro Chagas
Fundação Oswaldo Cruz
Rio de Janeiro - Brasil
Av. Brasil 4365,
CEP 21040-360,
Tel 55 21 3865-9648
email: pedro.brasil@ipec.fiocruz.br
email: emmanuel.brasil@gmail.com

---Apoio aos softwares livres
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www.broffice.org ou www.libreoffice.org - textos, planilhas ou
apresentações.
www.epidata.dk - entrada de dados.
www.r-project.org - análise de dados.
www.ubuntu.com - sistema operacional

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