STATS_WSR_TEST
is a Wilcoxon Signed Ranks test of paired samples to determine whether the median of the differences between the samples is significantly different from zero. The absolute values of the differences are ordered and assigned ranks. Then the null hypothesis states that the sum of the ranks of the positive differences is equal to the sum of the ranks of the negative differences.
This function takes three arguments: expr1
and expr2
are the two samples being analyzed, and the third argument is a return value of type VARCHAR2
. If you omit the third argument, the default is TWO_SIDED_SIG
. The meaning of the return values is shown in Table 510.
Table 510 STATS_WSR_TEST_* Return Values
Return Value  Meaning 


The observed value of Z 

Onetailed significance of Z 

Twotailed significance of Z 
Onesided significance is always with respect to the upper tail. The high value—that is, the value whose rejection region is the upper tail—is expr1
.