Based on the analysis of the characters of vehicle running on constrained and unconstrained condition on the urban freeway,this article a- dopted rank correlation coefficient to measure the interaction of vehicles and to determine the free flow.

Then,using rank correlation coefficient method to quantificationally analyze the water quality transform trend of the three segments.

A new method for evaluating the sensitivity of system parameters is put forward using Spearman coefficient in non-parameter statistics with an application example given.

Based on the practical monitoring data of Suya lake reservoir,an assessment of ground water quality and eutrophication for the reservoir was carried out by the use of the methods of indices and variation tendency of water quality was analyzed and appraised by the use of the spearman.

Based on the datasets from sampling plots, and by using Fisher’s exact test for 2×2 contingency table, Pearson correlation coefficient and Spearman rank correlation coefficient, the interspecific relationships between 24 dominants of wetland vegetation in Shanxi section of Yellow River were studied.

89,based on χ~2-test for 2×2 contingency table,Pearson correlation coefficient test,and Spearman rank correlation coefficient test,respectively.

The concepts of Kendall coefficient of concordance and Spearman rank correlation coefficient are elaborated in this paper.