Re: [R] Cohen's Kappa

...many thanks for all the answers and clarity!!! regards, christian Hi, Chance is not .5 in your data, it's a function of the expected values for presence and absence: (((7792*10855)/11974) + ((4182*1119)/11974))/11974 [1] 0.6225686 (.6862368-.6225686)/(1-.6225686)

Re: [R] Cohen's Kappa

See also section 6.4 of http://www.psych.upenn.edu/~baron/rpsych/rpsych.html which also points to a few packages that have kappa code in them. -- Jonathan Baron, Professor of Psychology, University of Pennsylvania Home page: http://www.sas.upenn.edu/~baron

[R] Cohen's Kappa

Hi, im little bit confused about Cohen's Kappa and i should be look into the Kappa function code. Is the easy formula really wrong? kappa=agreement-chance/(1-chance) many thanks christian ### true-negativ:7445

Re: [R] Cohen's Kappa

Shouldn't that be kappa = rater1 - rater2 / (1-chance) ? Andy -- Andrew J Perrin - andrew_perrin (at) unc.edu - http://perrin.socsci.unc.edu Assistant Professor of Sociology; Book Review Editor, _Social Forces_ University of

Re: [R] Cohen's Kappa

Hi, Chance is not .5 in your data, it's a function of the expected values for presence and absence: (((7792*10855)/11974) + ((4182*1119)/11974))/11974 [1] 0.6225686 (.6862368-.6225686)/(1-.6225686) [1] 0.1686881 Scot On Thu, 22 Mar 2007, Christian Schulz wrote: Hi, im little bit

Re: [R] Cohen's Kappa

Cohen, J. (1960). A coefficient of agreement for nominal scales. Educational and Psychological Measurement, 20, 37-46. Cohen, J. (1968). Weighted kappa: Nominal scale agreement with provision for scaled disagreement or partial credit. Psychological Bulletin, 70, 213-220. Francisco Dr.