Re: st: Need Help with Clusters and Weighting

[Steven Samuels <sjhsamuels@earthlink.net>]

Liliana,  The information that you have provided is not detailed  
enough for me to provide you much help. I cannot tell from your  
description, for example, if your data ARE a valid probability sample  
of Harris County.  What was the sampling frame? Was it an area  
sample? What were the 'strata'; what were 'clusters'? How were they  
selected? What were 'samples'?  How were THEY selected? Was each  
'sample' one person? What were the probabilities of selection.

The way that you phrase your questions suggests that you are on the  
right track, but don't have much knowledge yet of sampling. I suggest  
that you consult with the survey scientists who designed the sample  
and also with the biostatistics faculty members who teach sampling at  
UTH. They will suggest a good book for background reading. Ask your  
advisor if one of them can be on your doctoral committee. Statalist  
is really not a good place to learn sampling, but we will be happy to  
help you with Stata commands once you understand the sample details.  
Make sure that you consult the Stata survey -help- and Survey Manual  
too.

Good luck!

-Steven

On Feb 14, 2008, at 6:14 PM, Rodriguez, Liliana F wrote:


> Hello Stata Users List,
>
> I'm working on my dissertation and need to analyze a small dataset  
> (n=210) by logistic regression (with odds ratios). I have nine  
> variables (all categorical or binomial) and my outcomes are binary  
> Y/N. Data was obtained conducting a survey from 7 samples in each  
> of 30 clusters. The clusters were soft-stratified in 3 groups  
> according to income levels, as low, medium and high.  I want to be  
> sure than my sample is representative of the population in Harris  
> County, Texas.
>
> Should I weight for the clustering to analyze within a stratum? If  
> yes, what are the commands?
>
> What are the commands to do weighting for the strata, and the  
> clustering, when analyzing over the entire sample?
>
> Do I use income levels, crude income, or the population in each  
> cluster as the weight?
>
> Thanks.... I still have a lot to learn.
>
> Liliana Rodriguez
> Houston, Texas
>
>
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