How to use population weights in SPSS Complex Samples

My previous posts discussed the p-values that the base module of SPSS reports for statistical significance tests using weighted data; these weights are not correct for probability-weighted analyses. Jon Peck informed me of SPSS Complex Samples, which can provide correct p-values for statistical significance tests for probability-weighted analyses. Complex Samples does not have the most intuitive setup, so this post describes the procedure for analyzing data using probability weights in SPSS Statistics 21.

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The dataset that I was working with had probability weights but no clustering or stratification, so the Stratify By and Clusters boxes remain empty in the image below.

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The next dialog box has options for Simple Systematic and Simple Sequential. Either method will work if Proportions are set to 1 in the subsequent dialog box.

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I conducted an independent samples t-test, so I selected the General Linear Model command below.

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Click the Statistics button in the image above and then click the t-test box in the image below to tell SPSS to conduct a t-test.

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Hit OK to get the output.

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The SPSS output above has the same p-value as the probability-weighted Stata output below.

rattan2012outputStata

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