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SPSS® 12.0 Command Syntax Reference

SPSS® 12.0 Command Syntax Reference

SPSS® 12.0 Command Syntax Reference

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CSPLAN 357<br />

Typically the previous weight variable is produced in an earlier stage of a<br />

stage-by-stage sample selection process. The CSSELECT procedure multiplies<br />

previous weights with those for the current stage to obtain final sampling<br />

weights.<br />

For example, suppose you wish to sample individuals within cities but only<br />

city data are available at the outset of the study. For the first stage of extraction<br />

a design plan is created that specifies that 10 cities are to be sampled<br />

from the active file. The PLANVARS subcommand specifies that sampling<br />

weights are to be saved under the name CityWeights:<br />

CSPLAN SAMPLE<br />

/PLAN FILE=’c:\survey\city.csplan’<br />

/PLANVARS SAMPLEWEIGHT=CityWeights<br />

/DESIGN CLUSTER=city<br />

/METHOD TYPE=PPS_WOR<br />

/MOS VARIABLE=SizeVar<br />

/SIZE VALUE=10.<br />

This plan would be executed using the CSSELECT procedure on an active file<br />

in which each case is a city.<br />

For the next stage of extraction, a design plan is created that specifies that 50<br />

individuals are to be sampled within cities. The design uses the PREVIOUS-<br />

WEIGHT keyword to specify that sample weights generated in the first stage<br />

are to be used when computing final sampling weights for selected individuals.<br />

Final weights are saved to variable FinalWeights.<br />

CSPLAN SAMPLE<br />

/PLAN FILE=’c:\survey\individuals.csplan’<br />

/PLANVARS PREVIOUSWEIGHT=CityWeights<br />

SAMPLEWEIGHT=FinalWeights<br />

/DESIGN STRATA=city<br />

/METHOD TYPE=SIMPLE_WOR<br />

/SIZE VALUE=50.<br />

The plan for stage two would be executed using the CSSELECT procedure on<br />

an active file in which cases represent individuals and both city and city<br />

weight are recorded for each individual. Note that city is identified as a stratification<br />

variable in this stage so individuals are sampled within cities.

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