In this paper we compare ten correlation coefficients using a three-step bootstrap approach (TSB). A three-step bootstrap is applied to determine the optimal repetitions, B, to estimate the standard error of the statistic with certain degree of accuracy. The coefficients in question are Pearson product moment (r), Spearman’s rho (ρ), Kendall’s tau (τ) , Spearman’s Footrule (Ft), Symmetric Footr...

We present a SAS macro for improved statistical inference for measures of association, including Pearson's correlation, Spearman's coefficient, and Kendall's coefficient. While the CORR procedure is a powerful tool for calculating and testing these coefficients, some analyses are lacking. For example, the CORR procedure does not incorporate recent theoretical improvements in confidence interval...

This article considers inference on correlation coefficients of bivariate log-normal distributions. We developed generalized confidence intervals and hypothesis tests for the correlation coefficient, and extended the results for comparing two independent correlations. Simulation studies show that the suggested methods work well even for small samples. The methods are illustrated using two pract...

We identify three different levels of correlation (pairwise relative ordering, network-wide ranking and prediction through linearity) that could be assessed between a computationally-light centrality metric and a computationally-heavy centrality metric for real-world networks. The Kendall's concordance-based correlation measure could be used to quantitatively assess how well we could consider t...

BACKGROUND Scoring systems have been widely used to evaluate the severity and activity of oral lichen planus (OLP). The aim of the present study was to compare two existing (one modified) scoring systems in the evaluation of OLP severity and correlation with pain. Three differently experienced raters were involved. MATERIALS AND METHODS Consecutive patients with OLP were assessed for pain usi...

maryam sadat salamati1, hossein zeinali2 ,ehdi yousefi3     1- ardestan branch, islamic azad university, ardestan, iran   2- esfahan agricultural and natural research center, isfahan, iran   3- assist. prof, payam noor university, isfahan, iran             received: 10 february 2011 accepted: 26 may 2011     * corresponding author: e-mail: [email protected]       abstract     in order to...