Mahalanobis Distance: A Multivariate Measure of Effect in Hypnosis Research

Sleep and Hypnosis: A Journal of Clinical Neuroscience and Psychopathology Volume 9, Number 2, Year 2007

Marty Sapp, Ed.D., Festus E. Obiakor, Ph.D., Amanda J. Gregas, and Steffanie Scholze

Mahalanobis distance, a multivariate measure of effect, can improve hypnosis research. When two groups of research participants are measured on two or more dependent variables, Mahalanobis distance can provide a multivariate measure of effect. Finally, Mahalanobis distance is the multivariate squared generalization of the univariate d effect size, and like other multivariate statistics, it can take into account the intercorrelation of variables.

Keywords: Mahalanobis distance, multivariate effect size, hypnosis research.