FACTOR VARIABLES=var_list
[ /METHOD = {CORRELATION, COVARIANCE} ]
[ /EXTRACTION={PC, PAF}]
[ /ROTATION={VARIMAX, EQUAMAX, QUARTIMAX, NOROTATE}]
[ /PRINT=[INITIAL] [EXTRACTION] [ROTATION] [UNIVARIATE] [CORRELATION] [COVARIANCE] [DET] [KMO] [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. It lists the variables which are to partake in the analysis.
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 will be used.
The /ROTATION subcommand is used to specify the method by which the extracted solution will be rotated.
Three methods are available: VARIMAX (which is the default), EQUAMAX, and QUARTIMAX.
If don't want any rotation to be performed, the word NOROTATE will prevent the command from performing any
rotation on the data. Oblique rotations are not supported.
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.
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 will be printed. This can be useful for visualizing
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(n) is specified, then coefficients whose absolute value is less
than n will not be printed. If the keyword DEFAULT is given, or if no /FORMAT subcommand is given, then no sorting is
performed, and all coefficients will be printed.
The /CRITERIA subcommand is used to specify how the number of extracted factors (components) are chosen.
If FACTORS(n) is
specified, where n is an integer, then n factors will be extracted. Otherwise, the MINEIGEN setting will
be used. MINEIGEN(l) requests that all factors whose eigenvalues are greater than or equal to l are extracted.
The default value of l is 1. The ECONVERGE and ITERATE settings have effect only when iterative algorithms for factor
extraction (such as Principal Axis Factoring) are used. ECONVERGE(delta) specifies that
iteration should cease when
the maximum absolute value of the communality estimate between one iteration and the previous is less than delta. The
default value of delta is 0.001.
The ITERATE(m) setting sets the maximum number of iterations to m. 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.