Measures of Correlation and Associated Tests

The CORR procedure in Base SAS software provides several nonparametric measures of association and associated tests. It computes Spearman's rank-order correlation, Kendall's tau- b , and Hoeffding's measure of dependence, and it provides tests for each of these statistics. PROC CORR also computes Spearman's partial rank-order correlation and Kendall's partial tau- b . Finally, PROC CORR computes Cronbach's coefficient alpha for raw and standardized variables . This statistic can be used to estimate the reliability coefficient. For a general discussion of correlations , formulas, interpretation, and examples, refer to the chapter on the CORR procedure in the Base SAS 9.1 Procedures Guide .

The FREQ procedure also provides some nonparametric measures of association: gamma, Kendall's tau- b , Stuart's tau- c ,Somer's D , and the Spearman rank correlation. The output includes the measure, the asymptotic standard error, confidence limits, and the asymptotic test that the measure equals zero. For the Spearman rank correlation, you can optionally request an exact p -value that the correlation is equal to zero. For more information, see Chapter 29, 'The FREQ Procedure.'