Chapter 68: The SURVEYFREQ Procedure


Overview

The SURVEYFREQ procedure produces one-way to n -way frequency and crosstabulation tables from sample survey data. These tables include estimates of population totals and proportions , and the corresponding standard errors. PROC SURVEYFREQ computes the variance estimates based on the sample design used to obtain the survey data. The design can be a complex multistage survey design with stratification, clustering, and unequal weighting . PROC SURVEYFREQ also provides design-based tests of independence and association between variables .

PROC SURVEYFREQ uses the Taylor expansion method to estimate sampling errors of estimators based on complex sample designs. This method is appropriate for all designs where the first-stage sample is selected with replacement, or where the first-stage sampling fraction is small, as it often is in practice. The Taylor expansion method obtains a linear approximation for the estimator and then uses the variance estimate for this approximation to estimate the variance of the estimate itself (Woodruff 1971, Fuller 1975). When there are clusters or primary sampling units (PSUs) in the sample design, the procedure estimates variance from the variation among PSUs. When the design is stratified, the procedure combines stratum variance estimates to compute the overall variance estimate.




SAS.STAT 9.1 Users Guide (Vol. 6)
SAS.STAT 9.1 Users Guide (Vol. 6)
ISBN: N/A
EAN: N/A
Year: 2004
Pages: 127

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