The rank correlation coefficient, rs, which involves less computation than the product moment correlation coefficient, r, can be used to indicate the degree of relationship between two elements. The methods is applicable in situations where the assumptions underlying distribution correlation theory may not be satisfied. Semiquantitative spectrographic analyses can be used to calculate rank correlations between elements because the results are already partly ranked in an analytical report.
Additional publication details
USGS Numbered Series
Semiquantitative spectrographic analysis and rank correlation in geochemistry