Originally Posted by

**marklee_csu**
Hello, can someone tell me how to compute the p-value in a rank-biserial correlation?

I understand the rank-biserial correlation coefficient is a function of the Mann–Whitney U test, and is a special case of Somers' d where one variable is dichotomous and the other is ordinal or continuous, but am not sure how to derive the p-value when doing rank-biserial correlations.

In SPSS, the output of Mann–Whitney produces a different p-value to Somers' d (in the latter case an "approximate significance" is generated) and I'd like to better understand the difference, as well as which of these—or neither?—would be best use when doing a rank-biserial correlation.

Any advice/guidance would be most greatly appreciated!

Many thanks in advance for any guidance!

Kind regards,

Mark Lee

Australia