On Sep 21, 2011, at 18:39 , Marc Schwartz wrote: > Jeremy, > > Correlation alone is irrelevant when comparing two separate sets of > measurements on the same specimen. Correlation does not mean good agreement, > but good agreement tends to infer high correlation.
Marc, I think Jeremy is well aware of that. He just said that the power to detect a (small) difference is higher when the correlation is higher. (Since V(X-Y) = 2*(1-rho)*sigma^2 if X and Y have the same variance sigma^2) -- Peter Dalgaard, Professor Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Email: pd....@cbs.dk Priv: pda...@gmail.com ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.