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From | "Joseph Coveney" <jcoveney@bigplanet.com> |
To | <statalist@hsphsun2.harvard.edu> |
Subject | st: Re: friedman test |
Date | Wed, 30 Nov 2011 02:04:03 +0900 |
Daniela Ferrante wrote: I have a question about friedman test. I tried to perform the friedman test with STATA, R software and SPSS but I get quite different p values with an equal p value with R and SPSS but different from STATA results. I am wondering why I get quite different results. I attach the data: 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 4,47 0,005 0,005 12,56 0,005 0,005 0,005 0,005 0,005 0,005 0,1 0,2 1,46 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 0,005 Using this data I obtain p=0,69 using STATA software but p=0,06 using R and SPSS software -------------------------------------------------------------------------------- Try the user-written command -emh- for Friedman's test. See below for your particular problem, and see www.sfu.ca/sasdoc/sashtml/stat/chap28/sect41.htm for more about the approach. You can install -emh- from SSC. Joseph Coveney . input double score1 double score2 double score3 score1 score2 score3 1. 0.005 0.005 0.005 2. 0.005 0.005 0.005 3. 0.005 0.005 4.47 4. 0.005 0.005 12.56 5. 0.005 0.005 0.005 6. 0.005 0.005 0.005 7. 0.1 0.2 1.46 8. 0.005 0.005 0.005 9. 0.005 0.005 0.005 10. 0.005 0.005 0.005 11. 0.005 0.005 0.005 12. 0.005 0.005 0.005 13. 0.005 0.005 0.005 14. 0.005 0.005 0.005 15. 0.005 0.005 0.005 16. 0.005 0.005 0.005 17. 0.005 0.005 0.005 18. 0.005 0.005 0.005 19. 0.005 0.005 0.005 20. end . . generate byte subject = _n . quietly reshape long score, i(subject) j(time) . emh score time, strata(subject) anova tr(rank) Extended Mantel-Haenszel (Cochran-Mantel-Haenszel) Stratified Test of Association ANOVA (Row Mean Scores) Statistic: Q (2) = 5.6000, P = 0.0608 Transformation: Ranks . . exit end of do-file * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/