FACTOR { VARIABLES=var_list, MATRIX IN ({CORR,COV}={*,file_spec}) } [ /METHOD = {CORRELATION, COVARIANCE} ] [ /ANALYSIS=var_list] [ /EXTRACTION={PC, PAF}] [ /ROTATION={VARIMAX, EQUAMAX, QUARTIMAX, PROMAX[(k)], NOROTATE}] [ /PRINT=[INITIAL] [EXTRACTION] [ROTATION] [UNIVARIATE] [CORRELATION] [COVARIANCE] [DET] [KMO] [AIC] [SIG] [ALL] [DEFAULT] ] [ /PLOT=[EIGEN] ] [ /FORMAT=[SORT] [BLANK(n)] [DEFAULT] ] [ /CRITERIA=[FACTORS(n)] [MINEIGEN(l)] [ITERATE(m)] [ECONVERGE (delta)] [DEFAULT] ] [ /MISSING=[{LISTWISE, PAIRWISE}] [{INCLUDE, EXCLUDE}] ]

The `FACTOR`

command performs Factor Analysis or Principal Axis Factoring on a dataset. It may be used to find
common factors in the data or for data reduction purposes.

The `VARIABLES`

subcommand is required (unless the `MATRIX IN`

subcommand is used).
It lists the variables which are to partake in the analysis. (The `ANALYSIS`

subcommand may optionally further limit the variables that
participate; it is useful primarily in conjunction with `MATRIX IN`

.)

If `MATRIX IN`

instead of `VARIABLES`

is specified, then the analysis
is performed on a pre-prepared correlation or covariance matrix file instead of on
individual data cases. Typically the matrix file will have been generated by
`MATRIX DATA`

(see MATRIX DATA) or provided by a third party.
If specified, `MATRIX IN`

must be followed by ‘`COV`’ or ‘`CORR`’,
then by ‘`=`’ and `file_spec` all in parentheses.
`file_spec` may either be an asterisk, which indicates the currently loaded
dataset, or it may be a file name to be loaded. See MATRIX DATA, for the expected
format of the file.

The `/EXTRACTION`

subcommand is used to specify the way in which factors
(components) are extracted from the data.
If `PC`

is specified, then Principal Components Analysis is used.
If `PAF`

is specified, then Principal Axis Factoring is
used. By default Principal Components Analysis is used.

The `/ROTATION`

subcommand is used to specify the method by which the
extracted solution is rotated. Three orthogonal rotation methods are available:
`VARIMAX`

(which is the default), `EQUAMAX`

, and `QUARTIMAX`

.
There is one oblique rotation method, *viz*: `PROMAX`

.
Optionally you may enter the power of the promax rotation `k`, which must be enclosed in parentheses.
The default value of `k` is 5.
If you don’t want any rotation to be performed, the word `NOROTATE`

prevents the command from performing any rotation on the data.

The `/METHOD`

subcommand should be used to determine whether the
covariance matrix or the correlation matrix of the data is
to be analysed. By default, the correlation matrix is analysed.

The `/PRINT`

subcommand may be used to select which features of the analysis are reported:

`UNIVARIATE`

A table of mean values, standard deviations and total weights are printed.`INITIAL`

Initial communalities and eigenvalues are printed.`EXTRACTION`

Extracted communalities and eigenvalues are printed.`ROTATION`

Rotated communalities and eigenvalues are printed.`CORRELATION`

The correlation matrix is printed.`COVARIANCE`

The covariance matrix is printed.`DET`

The determinant of the correlation or covariance matrix is printed.`AIC`

The anti-image covariance and anti-image correlation matrices are printed.`KMO`

The Kaiser-Meyer-Olkin measure of sampling adequacy and the Bartlett test of sphericity is printed.`SIG`

The significance of the elements of correlation matrix is printed.`ALL`

All of the above are printed.`DEFAULT`

Identical to`INITIAL`

and`EXTRACTION`

.

If `/PLOT=EIGEN`

is given, then a “Scree” plot of the eigenvalues is
printed. This can be useful for visualizing the factors and deciding
which factors (components) should be retained.

The `/FORMAT`

subcommand determined how data are to be
displayed in loading matrices. If `SORT`

is specified, then
the variables are sorted in descending order of significance. If
`BLANK(`

is specified, then coefficients whose absolute
value is less than `n`)`n` are not printed. If the keyword
`DEFAULT`

is specified, or if no `/FORMAT`

subcommand is
specified, then no sorting is performed, and all coefficients are printed.

You can use the `/CRITERIA`

subcommand to specify how the number of
extracted factors (components) are chosen. If `FACTORS(`

is
specified, where `n`)`n` is an integer, then `n` factors are
extracted. Otherwise, the `MINEIGEN`

setting is used.
`MINEIGEN(`

requests that all factors whose eigenvalues
are greater than or equal to `l`)`l` are extracted. The default value
of `l` is 1. The `ECONVERGE`

setting has effect only when
using iterative algorithms for factor extraction (such as Principal Axis
Factoring). `ECONVERGE(`

specifies that
iteration should cease when the maximum absolute value of the
communality estimate between one iteration and the previous is less
than `delta`)`delta`. The default value of `delta` is 0.001.

The `ITERATE(`

may appear any number of times and is
used for two different purposes. It is used to set the maximum number
of iterations (`m`)`m`) for convergence and also to set the maximum
number of iterations for rotation.
Whether it affects convergence or rotation depends upon which
subcommand follows the `ITERATE`

subcommand.
If `EXTRACTION`

follows, it affects convergence.
If `ROTATION`

follows, it affects rotation.
If neither `ROTATION`

nor `EXTRACTION`

follow a
`ITERATE`

subcommand, then the entire subcommand is ignored.
The default value of `m` is 25.

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`

subcommand contains a missing value.

If `PAIRWISE`

is set, then a case is considered missing only if
either of the values for the particular coefficient are missing.
The default is `LISTWISE`

.