SIZE Subcommand (CSPLAN command)

The SIZE subcommand specifies the number of sampling units to draw at the current stage.

  • You can specify a single value, a variable name, or a matrix of counts for design strata.
  • Size values must be positive integers.
  • The SIZE subcommand is ignored with a warning if the PPS_MURTHY or PPS_BREWER method is specified.
  • The SIZE or RATE subcommand must be specified for each stage. An error occurs if both are specified.

VALUE. Apply a single value to all strata. For example, VALUE=10 selects 10 units per stratum.

MATRIX. Specify disproportionate sample sizes for different strata. Specify one or more variables after the MATRIX keyword. Then provide one size specification per stratum. A size specification includes a set of category values and a size value. Category values should be listed in the same order as variables to which they apply. Semicolons are used to separate the size specifications.

For example, the following syntax selects 10 units from the North stratum and 20 from the South stratum:

/SIZE MATRIX=region;  'North' 10; 'South' 20

If there is more than one variable, specify one size per combination of strata. For example, the following syntax specifies rate values for combinations of Region and Sex strata:

/SIZE MATRIX=region sex; 'North' 'Male' 10; 'North' 'Female'15; 
                         'South' 'Male' 24; 'South' 'Female' 30
  • The variable list must contain all or a subset of stratification variables from the same and previous stages and cluster variables from the previous stages. An error occurs if the list contains variables that are not defined as strata or cluster variables.
  • Each size specification must contain one category value per variable. If multiple size specifications are provided for the same strata or combination of strata, only the last one is honored.
  • String and date category values must be quoted.
  • A semicolon must appear after the variable list and after each size specification. The semicolon is not allowed after the last size specification.

VARIABLE. Specify the name of a single variable that contains the sample sizes.