R help - Dec 2009 - Cohen's kappa, unequal score ranges

Hi,

I am having problems getting cohen's kappa to work. I have been using the
function:
><-ckappa(x,y)
from the psy package.

I am trying to test for inter-observer reliability, I have 2 observers and 26
categories, however, the two observers might not necessarily have the same range
of categories (I have unequal score ranges). However, I thought R could cope
with this.

Each time I try the function above I get the following output:
>Error in ckappa(ob1, ob2) : unused argument(s) (ob2)
I got this even when I altered the data to have equal score ranges, therefore I
am not sure what this means or what I should do!!

Any help in this area would be much appreciated, or anything about the best way
to deal with inter-observer reliability (my data is all categorical),

Thanks,

Julia.

On 12/23/2009 01:58 AM, Julia Myatt wrote:
> Hi,
>
> I am having problems getting cohen's kappa to work. I have been using
the function:
>
>    
>> <-ckappa(x,y)
>>      
> from the psy package.
>
> I am trying to test for inter-observer reliability, I have 2 observers and
26 categories, however, the two observers might not necessarily have the same
range of categories (I have unequal score ranges). However, I thought R could
cope with this.
>
> Each time I try the function above I get the following output:
>
>    
>> Error in ckappa(ob1, ob2) : unused argument(s) (ob2)
>>      
> I got this even when I altered the data to have equal score ranges,
therefore I am not sure what this means or what I should do!!
>
> Any help in this area would be much appreciated, or anything about the best
way to deal with inter-observer reliability (my data is all categorical),
>
>    
Hi Julia,
The ckappa function only takes one argument, a rater by object matrix or 
dataframe of scores. Try:

ckappa(cbind(ob1,ob2))

Jim