A new correlation coefficient, its orthogonal decomposition and associated tests of independence

dc.creatorBergsma, Wicher P.
dc.date2006-04-28
dc.date.accessioned2026-07-07T08:07:45Z
dc.date.available2026-07-07T08:07:45Z
dc.descriptionA possible drawback of the ordinary correlation coefficient $ρ$ for two real random variables $X$ and $Y$ is that zero correlation does not imply independence. In this paper we introduce a new correlation coefficient $ρ^*$ which assumes values between zero and one, equalling zero iff the two variables are independent and equalling one iff the two variables are linearly related. The coefficients $ρ^*$ and $ρ^2$ are shown to be closely related algebraically, and they coincide for distributions on a $2\times 2$ contingency table. We derive an orthogonal decomposition of $ρ^*$ as a positively weighted sum of squared ordinary correlations between certain marginal eigenfunctions. Estimation of $ρ^*$ and its component correlations and their asymptotic distributions are discussed, and we develop visual tools for assessing the nature of a possible association in a bivariate data set. The paper includes consideration of grade (rank) versions of $ρ^*$ as well as the use of $ρ^*$ for contingency table analysis. As a special case a new generalization of the Cram{é}r-von Mises test to $K$ ordered samples is obtained.
dc.identifierhttps://arxiv.org/abs/math/0604627
dc.identifierhttp://arxiv.org/abs/math/0604627
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/131036
dc.subjectStatistics Theory
dc.subjectPrimary 62H20; secondary 62E99
dc.titleA new correlation coefficient, its orthogonal decomposition and associated tests of independence
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