STATS_CROSSTAB

Syntax

Description of stats_crosstab.gif follows
Description of the illustration ''stats_crosstab.gif''

Purpose

Crosstabulation (commonly called crosstab) is a method used to analyze two nominal variables. The STATS_CROSSTAB function takes three arguments: two expressions and a return value of type VARCHAR2. expr1 and expr2 are the two variables being analyzed. The function returns one number, determined by the value of the third argument. If you omit the third argument, then the default is CHISQ_SIG. The meaning of the return values is shown in Table 5-4.

Table 5-4 STATS_CROSSTAB Return Values

Return Value Meaning

CHISQ_OBS

Observed value of chi-squared

CHISQ_SIG

Significance of observed chi-squared

CHISQ_DF

Degree of freedom for chi-squared

PHI_COEFFICIENT

Phi coefficient

CRAMERS_V

Cramer's V statistic

CONT_COEFFICIENT

Contingency coefficient

COHENS_K

Cohen's kappa


STATS_CROSSTAB Example The following example determines the strength of the association between gender and income level:

SELECT STATS_CROSSTAB
         (cust_gender, cust_income_level, 'CHISQ_OBS') chi_squared,
       STATS_CROSSTAB
         (cust_gender, cust_income_level, 'CHISQ_SIG') p_value,
       STATS_CROSSTAB
         (cust_gender, cust_income_level, 'PHI_COEFFICIENT') phi_coefficient
  FROM sh.customers;

CHI_SQUARED    P_VALUE PHI_COEFFICIENT
----------- ---------- ---------------
 251.690705 1.2364E-47      .067367056