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Re: st: RE: Kappa query - unequal distribution of scores
From
Nick Cox <[email protected]>
To
[email protected]
Subject
Re: st: RE: Kappa query - unequal distribution of scores
Date
Thu, 22 Sep 2011 11:43:54 +0100
. bootstrap r(kappa), nodots reps(10000): kap rev1 rev2
[...]
Bootstrap results Number of obs = 83
Replications = 10000
command: kap rev1 rev2
_bs_1: r(kappa)
------------------------------------------------------------------------------
| Observed Bootstrap Normal-based
| Coef. Std. Err. z P>|z| [95% Conf. Interval]
-------------+----------------------------------------------------------------
_bs_1 | .020649 .0983171 0.21 0.834 -.172049 .213347
------------------------------------------------------------------------------
The s.e. is a bit higher. In this case, as kappa is almost 0, it is
pretty much immaterial what s.e. you get.
Nick
On Thu, Sep 22, 2011 at 10:36 AM, Nick Cox <[email protected]> wrote:
> I'd think about bootstrapping here.
> On Thu, Sep 22, 2011 at 10:06 AM, Downs, Sara
> <[email protected]> wrote:
>> Hi,
>>
>> I am trying to calculate agreement between 2 distributions of scores.
>> There are 3 possible scores: One score predominates and the other 2 are
>> extremely rare :
>>
>> tab rev1 rev2
>>
>> | rev2
>> rev1 | 0 1 2 | Total
>> -----------+---------------------------------+----------
>> 0 | 1 6 0 | 7
>> 1 | 13 57 3 | 73
>> 2 | 0 2 1 | 3
>> -----------+---------------------------------+----------
>> Total | 14 65 4 | 83
>>
>>
>> . kap rev1 rev2
>>
>> Expected
>> Agreement Agreement Kappa Std. Err. Z Prob>Z
>> -----------------------------------------------------------------
>> 71.08% 70.47% 0.0206 0.0852 0.24 0.4042
>>
>>
>> I understand that the usual kappa statistic is not reliable in this
>> situation . Is there any way in STATA that I can adjust for the high
>> expected frequency. I am using STATA 10.1.
>>
>
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