Used to compare the degree of consensus between
raters (inspectors) in, for example, Measurement
Systems Analysis. It uses a contingency table
approach.
Two raters inspect 150 parts independently and
make the following determinations:



Bret 



Reject 
Accept 
Total 

Reject 
20 
19 
39 
Alice 
Accept 
1 
110 
111 

Total 
21 
129 
150 
The expected values in each cell would be:



Bret 



Reject 
Accept 
Total 

Reject 
5.46 
33.54 
39 
Alice 
Accept 
15.54 
95.46 
111 

Total 
21 
129 
150 
These are the values that would give the same
totals if the determinations were made by pure
chance and is calculated from:
(row total x column total)/overall
total
The Kappa statistic is calculated from:
where:
Actual 
the number of times the
appraisers agreed (110 + 20 = 130) 
Expected 
the number of times they
would have agreed by chance (5.46 + 95.46) 
Trials 
the number of trials 
The value of Kappa will be between 0 and 1.
If the results were made by chance, neither rater
showing judgment the value would be zero. If the
raters were in perfect agreement, the number of
agreements would equal the number of trials and
Kappa would be 1.
