Kappa Value is a statistic used to determine the goodness of the measurement system in Attribute Agreement Analysis. It is the proportion of times the appraisers agreed to the maximum proportion of the times they could agree (both corrected for chance agreement). It is used when the appraisers evaluate the same samples and give nominal or ordinal ratings. It ranges from -1 to 1. Higher the Kappa value, higher the agreement.
If Kappa = 1, perfect agreement exists
If Kappa = 0, the agreement is the same as would be expected by chance
If Kappa < 0, the agreement is weaker than expected by chance (Kappa rarely goes negative)
Kendall's Coefficient of Concordance is a statistic used to determine the goodness of the measurement system in Attribute Agreement Analysis. It indicates the degree of association of ordinal assessments made by multiple appraisers when assessing the same samples. It is used instead of Kappa value when the rating scale is ordinal with more than 3 levels of ratings. Kendall's coefficient accounts for the order of the ratings (Kappa value does not account for it). It ranges from 0 to 1. Higher the coefficient, higher the agreement
An application-oriented question on the topic along with responses can be seen below. The best answer was provided by
Amlan Dutt on 07th June 2019.
Applause for all the respondents- Amlan Dutt, Sreyash Sangam.