Re: where can I learn about frequencies adjusting for population characteristics

Posted by Ryan on Apr 13, 2013; 2:15pm
URL: http://spssx-discussion.165.s1.nabble.com/Re-where-can-I-learn-about-frequencies-adjusting-for-population-characteristics-tp5719428p5719450.html

I cannot find the original post in my inbox, so I will just respond to this post. This post is not intended to be a response to Jon's comments.

 

I am not entirely certain what you are asking...

 

If you want to adjust for group differences on key characteristics, one simple approach would be to employ a binary logistic regression where group membership is the dependent variable, and the key characteristics for which you want to adjust are the predictors. Output the predicted probabilities and use those as a covariate in the model.

 

Important point: While you want to adjust for group differences, you should hope to not find significant group differences on those characteristics. That is, when you employ the logistic regression, you should hope that the key characteristics do not significantly/substantially predict group membership. The more they do, the less valid this endeavour becomes. More complex and perhaps optimal approaches have been developed, but I do not have time to expound upon them.

 

HTH,

 

Ryan

 

On Fri, Apr 12, 2013 at 11:50 AM, John F Hall <[hidden email]> wrote:

Gene

 

One way might involve devising some complex weighting, about which I know next to nothing.

 

Another way would be to produce conditional frequency tables (or contingency tables) and barcharts for sub-populations from each group.

 

If you have the raw data files, Excel spreadsheets or SPSS saved files for your groups and are prepared to send them to me (in confidence) I can have a look at your data and run some analyses for you.

 

As everyone knows, a picture (or chart) is worth a thousand words, and, as my old boss Mark Abrams used to say, “If it’s worth saying, you can say it in percentages.”

 

I’m copying the SPSS list into this as there are some really clever guys out there who may have helpful suggestions.

 

 

John F Hall (Mr)

[Retired academic survey researcher]

 

Email:   [hidden email] 

Website: www.surveyresearch.weebly.com

Start page:  www.surveyresearch.weebly.com/spss-without-tears.html

  

 

 

 

 

 

From: Survey Research Methods Section of the ASA [mailto:[hidden email]] On Behalf Of Gene Shackman
Sent: 12 April 2013 17:01
To: [hidden email]
Subject: where can I learn about frequencies adjusting for population characteristics

 

Hi all

We have some survey data from two different groups. Their population characteristics are slightly different (e.g., age, race/ethnicity, etc.). Where can I learn how to adjust them so that I can present their responses to survey questions, adjusted for their population characteristics? So for example I want to present tables showing what percent from groups 1 and 2 said they were satisfied with ABCDE, after making them comparable for the various population characteristics. That way, people can see, from the table, where there are differences.

I know I can do regressions to adjust, and get statistically significant differences, but I want to have easy to read tables too, that non statisticians can read.

Where on the web shows how to do this?

Thanks

Gene

Gene Shackman, Ph.D.
NYS DOH - Division of Nutrition
Evaluation, Research and Surveillance Unit
150 Broadway, Riverview Center, Suite 517
Albany NY 12204

<a href="tel:518%20402%207304" target="_blank" value="[phone]">518 402 7304      gxs03 at health.state.ny.us

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