Correlation: Parametric and Nonparametric Measures

Correlations, in general, and the Pearson product-moment correlation in particular, can be used for many research purposes, ranging from describing a relationship between two variables as a descriptive statistic to examining a relationship between two variables in a population as an inferential statistic, or to gauge the strength of an effect, or to conduct a meta-analytic study. How can correlation be more effectively used so that one doesn′t misinterpret the data? This book reveals how to do this by examining Pearson r from its conceptual meaning, to assumptions, special cases of the Pearson r, the biserial coefficient and tetrachoric coefficient estimates of the Pearson r, its uses in research (including effect size, power analysis, meta-analysis, utility analysis, reliability estimates and validation), factors that affect the Pearson r, and finally to additional nonparametric correlation indexes. After reading this book, the reader will be able to compare and distinguish the concepts of similarity and relationship, identify the distinction between correlation and causation, and to interpret correlations correctly.

The goals of my research programs are to improve the quality of individual well-being, and to build a healthy workplace and society that enhance the safety and health of workers and their families. A healthy workplace or a healthy society is one in which all constituents are able to exercise their talents and gifts to achieve high performance as well as maintain psychological and physical well-being. In order to understand how to effectively build a healthy society and a healthy organization, I have taken an interdisciplinary approach over years to explore the ways of maximizing organizational as well as societal productivity, and optimizing individual potentials to pursue healthier, more secure, and safer lives. My past field and military experience have convinced me that there will be much more efficient options available if one is open to different approaches and ideas, and utilize their strengths to solve problems.