Re: [R] Post-Hoc tests for Friedman Test?
Hello David, I wanted to thank you for pointing to this code for performing posthoc friedman test. I just used this example to create a function to perform this test (and also added some illustrative flexible plots to the mix), here: http://www.r-statistics.com/2010/02/post-hoc-analysis-for-friedmans-test-r-code/ Best, Tal Contact Details:--- Contact me: tal.gal...@gmail.com | 972-52-7275845 Read me: www.talgalili.com (Hebrew) | www.biostatistics.co.il (Hebrew) | www.r-statistics.com (English) -- On Mon, Sep 21, 2009 at 3:35 AM, David Winsemius dwinsem...@comcast.netwrote: On Sep 20, 2009, at 9:05 PM, j...@terraspark.com wrote: Hi there all, This is my first post to the list and I'll first say a few things: - R is great! - The archives of this list have helped me solve all of my problems/questions so far - I only know enough statistics to be dangerous I'm looking for a way to do post-hoc tests for the Friedman test. I have a dataset from a within-subjects design with 5 conditions where some of the dependent variables are ordinal, resulting from (summed) likert-scaled questionnaire data. From what I've read, I could use a wilcox.test on pairs of conditions and adjust the p level, but is there something in R that does a better job/automates this. I've seen references to the npmc package but that doesn't seem to do what I'm looking for, because it only accepts a data frame with two columns - i.e. there's no way to specify grouping/subject identifiers. Thanks, There is a worked example in the coin package for using a permutation test to examine differences after a Friedman test. The authors, Hothorn , Hornik , van de Wiel, and Zeileis, call this method the Wilcoxon-Nemenyi-McDonald-Thompson test and cite: Hollander Wolfe (1999), page 295 http://finzi.psych.upenn.edu/R/library/coin/html/SymmetryTests.html -- David Winsemius, MD Heritage Laboratories West Hartford, CT __ 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. [[alternative HTML version deleted]] __ 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.
Re: [R] Post-Hoc tests for Friedman Test?
On Sep 20, 2009, at 9:35 PM, David Winsemius wrote: On Sep 20, 2009, at 9:05 PM, j...@terraspark.com wrote: Hi there all, This is my first post to the list and I'll first say a few things: - R is great! - The archives of this list have helped me solve all of my problems/ questions so far - I only know enough statistics to be dangerous I'm looking for a way to do post-hoc tests for the Friedman test. I have a dataset from a within-subjects design with 5 conditions where some of the dependent variables are ordinal, resulting from (summed) likert-scaled questionnaire data. From what I've read, I could use a wilcox.test on pairs of conditions and adjust the p level, but is there something in R that does a better job/automates this. I've seen references to the npmc package but that doesn't seem to do what I'm looking for, because it only accepts a data frame with two columns - i.e. there's no way to specify grouping/subject identifiers. Thanks, There is a worked example in the coin package for using a permutation test to examine differences after a Friedman test. The authors, Hothorn , Hornik , van de Wiel, and Zeileis, call this method the Wilcoxon-Nemenyi-McDonald-Thompson test and cite: Hollander Wolfe (1999), page 295 http://finzi.psych.upenn.edu/R/library/coin/html/SymmetryTests.html A further option just presented itself during a search for an unrelated question: The MTP function in the multtest package has a robust=TRUE set of methods with these equivalencies offered: t.onesamp or t.pair: Wilcoxon signed rank, wilcox.test with y=NULL or paired=TRUE, t.twosamp.equalvar: Wilcoxon rank sum or Mann-Whitney, wilcox.test, f: Kruskal-Wallis rank sum, kruskal.test, f.block:Friedman rank sum, friedman.test, f.twoway: Friedman rank sum, friedman.test, http://finzi.psych.upenn.edu/R/library/multtest/html/MTP.html -- David Winsemius, MD Heritage Laboratories West Hartford, CT __ 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.
[R] Post-Hoc tests for Friedman Test?
Hi there all, This is my first post to the list and I'll first say a few things: - R is great! - The archives of this list have helped me solve all of my problems/questions so far - I only know enough statistics to be dangerous I'm looking for a way to do post-hoc tests for the Friedman test. I have a dataset from a within-subjects design with 5 conditions where some of the dependent variables are ordinal, resulting from (summed) likert-scaled questionnaire data. From what I've read, I could use a wilcox.test on pairs of conditions and adjust the p level, but is there something in R that does a better job/automates this. I've seen references to the npmc package but that doesn't seem to do what I'm looking for, because it only accepts a data frame with two columns - i.e. there's no way to specify grouping/subject identifiers. Thanks, Jon Marbach PhD Student, Computer Science Department University of Colorado __ 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.
Re: [R] Post-Hoc tests for Friedman Test?
On Sep 20, 2009, at 9:05 PM, j...@terraspark.com wrote: Hi there all, This is my first post to the list and I'll first say a few things: - R is great! - The archives of this list have helped me solve all of my problems/ questions so far - I only know enough statistics to be dangerous I'm looking for a way to do post-hoc tests for the Friedman test. I have a dataset from a within-subjects design with 5 conditions where some of the dependent variables are ordinal, resulting from (summed) likert-scaled questionnaire data. From what I've read, I could use a wilcox.test on pairs of conditions and adjust the p level, but is there something in R that does a better job/automates this. I've seen references to the npmc package but that doesn't seem to do what I'm looking for, because it only accepts a data frame with two columns - i.e. there's no way to specify grouping/subject identifiers. Thanks, There is a worked example in the coin package for using a permutation test to examine differences after a Friedman test. The authors, Hothorn , Hornik , van de Wiel, and Zeileis, call this method the Wilcoxon-Nemenyi-McDonald-Thompson test and cite: Hollander Wolfe (1999), page 295 http://finzi.psych.upenn.edu/R/library/coin/html/SymmetryTests.html -- David Winsemius, MD Heritage Laboratories West Hartford, CT __ 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.
