12.4 CROSSTABS

     CROSSTABS
             /TABLES=var_list BY var_list [BY var_list]...
             /MISSING={TABLE,INCLUDE,REPORT}
             /WRITE={NONE,CELLS,ALL}
             /FORMAT={TABLES,NOTABLES}
                     {LABELS,NOLABELS,NOVALLABS}
                     {PIVOT,NOPIVOT}
                     {AVALUE,DVALUE}
                     {NOINDEX,INDEX}
                     {BOX,NOBOX}
             /CELLS={COUNT,ROW,COLUMN,TOTAL,EXPECTED,RESIDUAL,SRESIDUAL,
                     ASRESIDUAL,ALL,NONE}
             /STATISTICS={CHISQ,PHI,CC,LAMBDA,UC,BTAU,CTAU,RISK,GAMMA,D,
                          KAPPA,ETA,CORR,ALL,NONE}
     
     (Integer mode.)
             /VARIABLES=var_list (low,high)...

The CROSSTABS procedure displays crosstabulation tables requested by the user. It can calculate several statistics for each cell in the crosstabulation tables. In addition, a number of statistics can be calculated for each table itself.

The TABLES subcommand is used to specify the tables to be reported. Any number of dimensions is permitted, and any number of variables per dimension is allowed. The TABLES subcommand may be repeated as many times as needed. This is the only required subcommand in general mode.

Occasionally, one may want to invoke a special mode called integer mode. Normally, in general mode, PSPP automatically determines what values occur in the data. In integer mode, the user specifies the range of values that the data assumes. To invoke this mode, specify the VARIABLES subcommand, giving a range of data values in parentheses for each variable to be used on the TABLES subcommand. Data values inside the range are truncated to the nearest integer, then assigned to that value. If values occur outside this range, they are discarded. When it is present, the VARIABLES subcommand must precede the TABLES subcommand.

In general mode, numeric and string variables may be specified on TABLES. Although long string variables are allowed, only their initial short-string parts are used. In integer mode, only numeric variables are allowed.

The MISSING subcommand determines the handling of user-missing values. When set to TABLE, the default, missing values are dropped on a table by table basis. When set to INCLUDE, user-missing values are included in tables and statistics. When set to REPORT, which is allowed only in integer mode, user-missing values are included in tables but marked with an M (for “missing”) and excluded from statistical calculations.

Currently the WRITE subcommand is ignored.

The FORMAT subcommand controls the characteristics of the crosstabulation tables to be displayed. It has a number of possible settings:

• TABLES, the default, causes crosstabulation tables to be output. NOTABLES suppresses them.
• LABELS, the default, allows variable labels and value labels to appear in the output. NOLABELS suppresses them. NOVALLABS displays variable labels but suppresses value labels.
• PIVOT, the default, causes each TABLES subcommand to be displayed in a pivot table format. NOPIVOT causes the old-style crosstabulation format to be used.
• AVALUE, the default, causes values to be sorted in ascending order. DVALUE asserts a descending sort order.
• INDEX/NOINDEX is currently ignored.
• BOX/NOBOX is currently ignored.

The CELLS subcommand controls the contents of each cell in the displayed crosstabulation table. The possible settings are:

COUNT

Frequency count.

ROW

Row percent.

COLUMN

Column percent.

TOTAL

Table percent.

EXPECTED

Expected value.

RESIDUAL

Residual.

SRESIDUAL

Standardized residual.

ASRESIDUAL

Adjusted standardized residual.

ALL

All of the above.

NONE

Suppress cells entirely.

/CELLS without any settings specified requests COUNT, ROW, COLUMN, and TOTAL. If CELLS is not specified at all then only COUNT will be selected.

The STATISTICS subcommand selects statistics for computation:

CHISQ

Pearson chi-square, likelihood ratio, Fisher's exact test, continuity correction, linear-by-linear association.

PHI

Phi.

CC

Contingency coefficient.

LAMBDA

Lambda.

UC

Uncertainty coefficient.

BTAU

Tau-b.

CTAU

Tau-c.

RISK

Risk estimate.

GAMMA

Gamma.

D

Somers' D.

KAPPA

Cohen's Kappa.

ETA

Eta.

CORR

Spearman correlation, Pearson's r.

ALL

All of the above.

NONE

No statistics.

Selected statistics are only calculated when appropriate for the statistic. Certain statistics require tables of a particular size, and some statistics are calculated only in integer mode.

/STATISTICS without any settings selects CHISQ. If the STATISTICS subcommand is not given, no statistics are calculated.

Please note: Currently the implementation of CROSSTABS has the followings bugs:

• Pearson's R (but not Spearman) is off a little.
• T values for Spearman's R and Pearson's R are wrong.
• Significance of symmetric and directional measures is not calculated.
• Asymmetric ASEs and T values for lambda are wrong.
• ASE of Goodman and Kruskal's tau is not calculated.
• ASE of symmetric somers' d is wrong.
• Approximate T of uncertainty coefficient is wrong.

Fixes for any of these deficiencies would be welcomed.