Hi All,

I am using raw data.

Following is an example of my data frame
       P1 P2 P3
H    1     1   1
M    2     4   2
L     2     2   2

H,M,L relate to the three cases, and P1 to P3 relate to the
raters/participants.

The problem I am having is if all the values are 1 in the above data frame
(say I have named it r1.df) and I use the following command
kappam.fleiss(r1.df) I get a negative kappa value.

Thanks and Regards

Mehdi E

On Tue, Jul 14, 2009 at 2:09 AM, William Revelle <lists@revelle.net> wrote:

>  At 6:48 PM +1200 7/13/09, mehdi ebrahim wrote:
>
>> Hi All,
>>
>> I am using fleiss kappa for inter rater agreement.  Are there any know
>> issues with Fleiss kappa calculation in R?  Even when I supply mock data
>> with total agreement among the raters I do not get a kappa value of 1.
>> instead I am getting negative values.
>>
>> I am using the irr package version 0.70
>>
>> Any help is much appreciated.
>>
>
> Mehdi,
>  Are you by any chance giving the function the agreement matrix rather than
> the raw data?  The  kappam.fliess function seems to want the ratings rather
> than the agreement matrix.
>
> Bill
>
>
> --
> William Revelle         http://personality-project.org/revelle.html
> Professor
> http://personality-project.org/personality.html
> Department of Psychology
> http://www.wcas.northwestern.edu/psych/
> Northwestern University http://www.northwestern.edu/
> Attend  ISSID/ARP:2009               http://issid.org/issid.2009/
>



-- 
Mehdi
(You want something? Go Get It! . - A pursuit for happiness )

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