on 12/07/2008 09:23 AM paul murima wrote: > Hi. > I have data which i would want to assess the degree of agreement > between two assays, e.g., to evaluate reproducibility or for > inter-rater reliability. I have used the Pearson product-moment > correlation coefficient. It looks good ranginging between 0.90 to > 0.998. Though this looks good. I am told the Concordance correlation > coefficient will give a better picture of how reproducible the assay > is. > Does any one know how to run such a test using R? If so can you kindly > provide the code, and bit of explanations to spruce it up? > > Thank you > > Paul
Look at the epi.ccc function in the epiR CRAN package. More information here: http://bm2.genes.nig.ac.jp/RGM2/R_current/library/epiR/man/epi.ccc.html You might also want to review Martin Bland's page pertaining to the design and analysis of measurement agreement studies: http://www-users.york.ac.uk/~mb55/meas/meas.htm HTH, Marc Schwartz ______________________________________________ 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.
