Spearman rank correlation coefficient

The mechanistic simulation ACAT model was modified to account automatically for the change in small intestinal and colon k as a function of the local (pH-dependent) log D of the drug molecule. The rank order of %HIA from GastroPlus was directly compared with rank order experimental %HIA with this correction for the log D of each molecule in each of the pH environments of the small intestine. A significant Spearman rank correlation coefficient for the mechanistic simulation-based method of 0.58 (p < 0.001) was found. The mechanistic simulation produced 71% of %HIA predictions within 25% of the experimental values. 

Trace element contents in rocks intersected by drill holes WB-08-03 to WB-08-06 are associated with altered rhyolite Spearman rank correlation coefficients for Ag, Mo and S with Au are moderate to high. Correlation coefficients for Au with As, Cu, Sb and Mo in drill hole WB08-11 (vuggy quartz) are moderate to high. These element correlations suggest that mineralization may be related to an epithermal system (Panteleyev 1995). 

For each IC50 bin, the percentage of compounds that list the ADR was calculated as percent ADR positive. For each group of seven IC50 bins, a Spearman rank correlation coefficient was calculated for the percent ADR positive relative to the bin rank. A strong Spearman correlation indicates a dose response in the ADR association. 

Apparently the oldest nonparametric measure of the strength of association between two factors [26], the Spearman rank correlation coefficient... 

While the Youden plot (Figure 3) indicates that there is systematic error in the various laboratories, a test by Spearmans rank correlation coefficient (Table Vb) is ambiguous. The ranking is significant at the 0.05 level but not at the 0.01 level thus a correlation of the ranks of the laboratories such as we see here would appear less than five times in 100 by chance but more than one time in 100. I prefer to look at these results in terms... 

As above represented it is necessary to test the ruggedness of FA against deviations from the normal distribution FA was, therefore, conducted on the basis of the SPEARMAN rank correlation coefficient [WEBER, 1986]. The obtained factor loading matrix... 

Several authors used the Spearman rank correlation coefficient as a MEP-SI in similarity investigations [112, 114, 115] ... 

Spearman rank correlation coefficient simiiarity/diversity... 

Figure 17.1 Correlation of rank order for ADMET Risk and human intestinal absorption (H IA%). The ADMET Risk score ranged from 0 to 5, with 5 being compounds with the greatest risk of having poor ADMET properties. Within a single ADMET Risk number, the compounds were ranked according to ascending estimated human jejunal permeability (ADMET Predictor, Simulations Plus, Inc.). Spearman rank correlation coefficient was 0.7 (pcO.OOl).

Figure 17.2 Correlation of rank order for 43 compounds that are known substrates for influx or efflux transporters. Spearman rank correlation coefficient was 0.3.

Spearman rank correlation coefficient statistical indices ( correlation measures)... 

The Spearman rank correlation coefficient, denoted as ps, is a widely used correlation measure between two ranked variables defined as... 

Another quick and dirty test for heteroscedasticity suggested by Carroll and Ruppert (1988) is to compute the Spearman rank correlation coefficient between absolute studentized residuals and predicted values. If Spearman s correlation coefficient is statistically significant, this is indicative of increasing variance, but in no manner should the degree of correlation be taken as a measure of the degree of heteroscedasticity. They also suggest that a further refinement to any residual plot would be to overlay a nonparametric smoothed curve, such as a LOESS or kernel fit. 

Relationships were tested with the non-parametric Spearman rank correlation coefficient, while the translocation capacity was tested with the ratio Ce/Cr, where Ce and Cr are the antimony contents in an epigeal compartment (shoots, leaves, etc.) and in the roots, respectively. The effects of plant traits were tested with the Mann-Whitney /-test in each sampling site for which a sample size no smaller than four observations was possible. The null hypothesis was not rejected when an overlap of observations between small samples occurred. 

Sometimes geochemical data cannot strictly be used in product-moment correlation of the type described above for they do not fuliil the requisite conditions. For example, some populations are not normally distributed and others include oudiers. An alternative, therefore, to Pearson s product-moment coefficient of linear correlation is the Spearman rank coefficent of correlation, usually designated r. This type of correlation is applicable to major or trace element data measured on a ranking scale rather than the equidistant scale used in Pearson s product-moment correlation. The Spearman rank correlation coefficient is calculated as follows ... 

The particular advantages of the Spearman rank correlation coefficient are (1) they alone are applicable to ranked data and (2) they are superior to the product- moment correlation coefficient when applied to populations that are not normally distributed and/or include outfiers. A further advantage 1 that the Spearman rank correlation coefficient (r,) is speedy to calculate and may be used as a quick approximation for the product-moment correlation coefficient (r). 

Grooming is highly correlated with aggressive behavior (r =0.74, p<0.01, Spearman rank correlation coefficient test the degree of aggressive behavior was determined by the amount of attacks and bites performed by the pair). 

Table 10 The Spearman rank correlation coefficient. Critical ...

Another statistical correlation tool called the Spearman rank correlation coefficient is more suitable for data that does not fulfill normal distribution and works better in detecting nonhnearity between two variables. The Spearman rank correlation coefficient was determined to be 0.928. Both values show high correlation between the experimental and the predicted model in Eq. 6.14. 

Spearman Rank correlation coefficients were calculated between FpA, FpB3 1- 2 and 8TG and lipid levels, alcohol consumption and weight since the latter data tend not to be distributed normally. Results are shown in Table III. Once again, inclusion of the two treated patients had no effect upon the correlation results. 

Significant differences between 2002 and 2005 are tested using the two independent samples (Anova t-test) as well as the longitudinal sample (Paired t-test). Spearmans rank correlation coefficients for non-parametric data are included in the correlation matrices. The data of the two... 

N mi s is the number mi sc 1 ass ified, and the figure in parentheses after the value of N mis is the number misclassified by two grades and Rg is the Spearman rank correlation coefficient for recognition by use of "the leave-one-out technique. 

The product-moment correlation coefficient is widely used in bmriate data analysis to measure the extent of the correlation between two variables, but it is not clear that it is necessarily appropriate to measure the extent of the similarity between two objects. Other sorts of correlation coefficient are available, such as the Spearman rank correlation coefficient which has been used by Manaut et al. as a measure of electrostatic similarity, but these have not found extensive application in similarity searching systems. Similar comments apply to probabilistic coefficients, which are calculated from the frequency distribution of descriptors in a database, and which Adamson and Bush < found to give poor results when applied to 2D chemical structures. 

Spearman Rank Correlation Coefficient n Also known as Spearman s rho or SRCC and usually designated by r or p, is a widely used nonparametric measure of the correlation between two variables. It is generally used when the values of the variables are ambiguous or hard... 

To identify any significant link between the extracted contributing factors from both types of the reports, the statistical dependencies of the factors are studied two-by-two using Pearson correlation coefficient (r). The reliabilities of the studies are tested using % -goodness-of-fit test. The Spearman rank correlation coefficient (p) is also used to study the rank relation between the frequencies of... 

The following simple example illustrates how ONR and SNR is calculated a scenario ranked nr 577 (concerning outage compensation or Styrel) among a total number of 1000 rank levels will be given the ONR/SNR (1000-577)71000 = 0.423. The ONR and SNR will always vary within the interval [0,1]. For the subset of scenarios without affected top priority customers (priority 0 or 1) the correlation between the two ranking methods are analysed. In order to do this we use Spearmans rank correlation coefficient. 

Table 4. Statistics of rankings over 50 independent draws of model (i) homogeneous system. For each test case, the mean and standard deviation of the Spearman rank correlation coefficient is shown.

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