STATS_CROSSTAB

Syntax

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