ONEWAY [/VARIABLES = ]var_listBYvar/MISSING={ANALYSIS,LISTWISE} {EXCLUDE,INCLUDE} /CONTRAST=value1[,value2] ... [,valueN] /STATISTICS={DESCRIPTIVES,HOMOGENEITY} /POSTHOC={BONFERRONI, GH, LSD, SCHEFFE, SIDAK, TUKEY, ALPHA ([value])}

The `ONEWAY`

procedure performs a one-way analysis of variance of
variables factored by a single independent variable.
It is used to compare the means of a population
divided into more than two groups.

The dependent variables to be analysed should be given in the `VARIABLES`

subcommand.
The list of variables must be followed by the `BY`

keyword and
the name of the independent (or factor) variable.

You can use the `STATISTICS`

subcommand to tell PSPP to display
ancillary information. The options accepted are:

- DESCRIPTIVES Displays descriptive statistics about the groups factored by the independent variable.
- HOMOGENEITY Displays the Levene test of Homogeneity of Variance for the variables and their groups.

The `CONTRAST`

subcommand is used when you anticipate certain
differences between the groups.
The subcommand must be followed by a list of numerals which are the
coefficients of the groups to be tested.
The number of coefficients must correspond to the number of distinct
groups (or values of the independent variable).
If the total sum of the coefficients are not zero, then PSPP will
display a warning, but will proceed with the analysis.
The `CONTRAST`

subcommand may be given up to 10 times in order
to specify different contrast tests.
The `MISSING`

subcommand defines how missing values are handled.
If `LISTWISE`

is specified then cases which have missing values for
the independent variable or any dependent variable are ignored.
If `ANALYSIS`

is specified, then cases are ignored if the independent
variable is missing or if the dependent variable currently being
analysed is missing. The default is `ANALYSIS`

.
A setting of `EXCLUDE`

means that variables whose values are
user-missing are to be excluded from the analysis. A setting of
`INCLUDE`

means they are to be included. The default is `EXCLUDE`

.

Using the `POSTHOC`

subcommand you can perform multiple
pairwise comparisons on the data. The following comparison methods
are available:

`LSD`

Least Significant Difference.`TUKEY`

Tukey Honestly Significant Difference.`BONFERRONI`

Bonferroni test.`SCHEFFE`

Scheffé’s test.`SIDAK`

Sidak test.`GH`

The Games-Howell test.

Use the optional syntax `ALPHA(`

to indicate that
`value`)`ONEWAY`

should perform the posthoc tests at a confidence level of
`value`. If `ALPHA(`

is not specified, then the
confidence level used is 0.05.
`value`)