T-TEST /MISSING={ANALYSIS,LISTWISE} {EXCLUDE,INCLUDE} /CRITERIA=CI(confidence) (One Sample mode.) TESTVAL=test_value/VARIABLES=var_list(Independent Samples mode.) GROUPS=var(value1[,value2]) /VARIABLES=var_list(Paired Samples mode.) PAIRS=var_list[WITHvar_list[(PAIRED)] ]

The `T-TEST`

procedure outputs tables used in testing hypotheses about
means.
It operates in one of three modes:

- One Sample mode.
- Independent Groups mode.
- Paired mode.

Each of these modes are described in more detail below. There are two optional subcommands which are common to all modes.

The `/CRITERIA`

subcommand tells PSPP the confidence interval used
in the tests. The default value is 0.95.

The `MISSING`

subcommand determines the handling of missing
variables.
If `INCLUDE`

is set, then user-missing values are included in the
calculations, but system-missing values are not.
If `EXCLUDE`

is set, which is the default, user-missing
values are excluded as well as system-missing values.
This is the default.

If `LISTWISE`

is set, then the entire case is excluded from analysis
whenever any variable specified in the `/VARIABLES`

, `/PAIRS`

or
`/GROUPS`

subcommands contains a missing value.
If `ANALYSIS`

is set, then missing values are excluded only in the analysis for
which they would be needed. This is the default.