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Preparing a Complex Sample for Analysis
This step allows you to identify the stratification and clustering variables and define sample
weights. You can also provide a label for the stage.
Strata. The cross-classification of stratification variables defines distinct subpopulations, or strata.
Your total sample represents the combination of independent samples from each stratum.
Clusters. Cluster variables define groups of observational units, or clusters. Samples drawn in
multiple stages select clusters in the earlier stages and then subsample units from the selected
clusters. When analyzing a data file obtained by sampling clusters with replacement, you should
include the duplication index as a cluster variable.
Sample Weight. You must provide sample weights in the first stage. Sample weights are computed
automatically for subsequent stages of the current design.
Stage Label. Youcanspecifyanoptionalstringlabelforeachstage.Thisisusedintheoutputto
help identify stagewise information.
Note: The source variable list has the same contents across steps of the Wizard. In other words,
variables removed from the source list in a particular step are removed from the list in all steps.
Variables returned to the source list show up in all steps.
Tree Controls for Navigating the Analysis Wizard
At the left side of each step of the Analysis Wizard is an outline of all the steps. You can navigate
the Wizard by clicking on the name of an enabled step in the outline. Steps are enabled as long as
all previous steps are valid—that is, as long as each previous step has been given the minimum
required specifications for that step. For more information on why a given step may be invalid,
see the Help for individual steps.