( P_Observed - P_Expected ) / ( 1 - P_Expected )
    ( P_Observed - .5 ) / ( 1 - .5 )이기 때문입니다.

입력변수는 관찰자들이 확실히 동의하거나(input A), 혹은 동의하지 않거나(input B), 혹은 가능한 두가지 조합의 동의하지 않음(input B와 C)을 의미합니다

참고문헌

MedCalc CrossRef: Kappa Multicalc Page

Cohen JA, A coefficient of agreement for nominal scales, Educ Psych Meas, 1960; 20:37-46

Cicchetti DV, Feinstein AR, High agreement but low kappa: II. Resolving the paradoxes, J Clin Epidemiol, 1990;43(6):551-558

Bennett EM, Albert R, Goldstein AC, Communications through limited response questioning, Public Opinion Q, 1954; 18:303-308

Byrt T, Bishop J, Carlin JB, Bias, prevalence and kappa, J Clin Epidem, 1993; v46 #5, 423-429