Display of Statistics (MVA command)

The following statistics can be displayed for a t test:

  • The t statistic, for comparing the means of two groups defined by whether the indicator variable is coded as missing or nonmissing. (See the topic Missing Indicator Variables (MVA command) for more information. )

    T. Display the t statistics. This setting is the default.

    NOT. Suppress the t statistics.

  • The degrees of freedom associated with the t statistic.

    DF. Display the degrees of freedom. This setting is the default.

    NODF. Suppress the degrees of freedom.

  • The probability (two-tailed) associated with the t test, calculated for the variable that is tested without reference to other variables. Care should be taken when interpreting this probability.

    PROB. Display probabilities.

    NOPROB. Suppress probabilities. This setting is the default.

  • The number of values in each group, where groups are defined by values that are coded as missing and present in the indicator variable.

    COUNTS. Display counts. This setting is the default.

    NOCOUNTS. Suppress counts.

  • The means of the groups, where groups are defined by values that are coded as missing and present in the indicator variable.

MEANS. Display means. This setting is the default.

NOMEANS. Suppress means.

Example

MVA VARIABLES=populatn density urban religion lifeexpf region
  /CATEGORICAL=region
  /ID=country
  /TTEST.
  • The TTEST subcommand produces a table of t tests. For each quantitative variable named in the variables list, a t test is performed, comparing the mean of the values for which the other variable is present against the mean of the values for which the other variable is missing.
  • The table displays default statistics, including values of t, degrees of freedom, counts, and means.