Displayed Output

The SURVEYMEANS Procedure

Displayed Output

By default PROC SURVEYMEANS displays a "Data Summary" table and a "Statistics" table. If you specify CLASS variables, or if you specify any character variables in the VAR statement, then the procedure displays a "Class Level Information" table. If you specify the LIST option in the STRATA statement, then the procedure displays a "Stratum Information" table.

Data and Sample Design Summary

The "Data Summary" table provides information on the input data set and the sample design. This table displays the total number of valid observations, where an observation is considered valid if it has nonmissing values for all procedure variables other than the analysis variables; that is, for all specified STRATA, CLUSTER, and WEIGHT variables. This number may differ from the number of nonmissing observations for an individual analysis variable, which the procedure displays in the "Statistics" table. See the section "Missing Values" for more information.

PROC SURVEYMEANS displays the following information in the "Data Summary" table:

Number of Strata, if you specify a STRATA statement
Number of Clusters, if you specify a CLUSTER statement
Number of Observations, which is the total number of valid observations
Sum of Weights, which is the sum over all valid observations, if you specify a WEIGHT statement

Class Level Information

If you use a CLASS statement to name classification variables for categorical analysis, or if you list any character variables in the VAR statement, then PROC SURVEYMEANS displays a "Class Level Information" table. This table contains the following information for each classification variable:

Class Variable, which lists each CLASS variable name
Levels, which is the number of values or levels of the classification variable
Values, which lists the values of the classification variable. The values are separated by a white space character; therefore, to avoid confusion, you should not include a white space character within a classification variable value.

Stratum Information

If you specify the LIST option in the STRATA statement, PROC SURVEYMEANS displays a "Stratum Information" table. This table displays the number of valid observations in each stratum, as well as the number of nonmissing stratum observations for each analysis variable. The "Stratum Information" table provides the following for each stratum:

Stratum Index, which is a sequential stratum identification number
STRATA variable(s), which lists the levels of STRATA variables for the stratum
Population Total, if you specify the TOTAL= option
Sampling Rate, if you specify the TOTAL= option or the RATE= option. If you specify the TOTAL= option, the sampling rate is based on the number of valid observations in the stratum.
N Obs, which is the number of valid observations
Variable, which lists each analysis variable name
N, which is the number of nonmissing observations for the analysis variable
Clusters, which is the number of clusters, if you specify a CLUSTER statement,

Statistics

The "Statistics" table displays all of the statistics that you request with statistic-keywords in the PROC SURVEYMEANS statement. If you do not specify any statistic-keywords, then by default this table displays the following information for each analysis variable: the sample size, the mean, the standard error of the mean, and the confidence limits for the mean. The "Statistics" table may contain the following information for each analysis variable, depending on which statistic-keywords you request:

Variable name
N, which is the number of nonmissing observations
N Miss, which is the number of missing observations
Minimum
Maximum
Range
number of Clusters
Sum of Weights
DF, which is the degrees of freedom for the t test
Mean
Std Error of Mean, which is the standard error of the mean
Var of Mean, which is the variance of the mean
t Value, for testing H₀: population MEAN = 0
Pr > | t |, which is the two-sided p-value for the t test
Lower and Upper $100(1 - \alpha)$ % CL for Mean, which are confidence limits for the mean
Coeff of Variation, which is the coefficient of variation
Sum
Std Dev, which is the standard deviation of the sum
Var of Sum, which is the variance of the sum
Lower and Upper $100(1 - \alpha)$ % CL for Sum, which are confidence limits for the sum

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