Kappa Value is a statistic used to determine the quality of the measurement system in the analysis of the compliance attribute. This is the proportion of periods during which evaluators accepted the maximum proportion of time they could agree (both corrected to random agreement). It is used when examiners evaluate the same samples and give nominal or ordinal assessments. It goes from -1 to 1. No more kappa, more agreement. When Kappa 1, the perfect match exists When Kappa 0, the agreement is the same as by chance if Kappa < 0, the agreement is lower than expected by chance (Kappa is rarely negative) Kendalls match coefficient is a statistic used to determine the quality of the measurement system in the analysis of attributes. It indicates the degree of association of ordinal assessments conducted by several examiners when evaluating the same samples. It is used in place of the Kappa value if the rating scale is ordered with more than 3 rating levels. The Kendall coefficient is the order of the ratings (the kappa value does not take them into account). It goes from 0 to 1. The higher the coefficient, the higher the agreement Consider two cubes (… Marsl-gner) that can have values of 0 to 7,100 times at the same time.
Kappa`s statistics are used to summarize the degree of agreement between councillors after the agreement was withdrawn by chance. It tests the correspondence between the evaluators and themselves (repeatability) and with each other (reproducibility). For more information on repeatability and reproducibility, see Gage R-R. Kappa`s statistics are the main metric used to measure how good or bad an attribute measurement system is. Kappa value is useful in the case of registrations of nominal attributes, taking in the data some names, symbols such as black, white; strong, weak, etc. Here, the recordings are organized in a categorical form and different observers provide a kind of ranking of the data in relation to its understanding. Subsequently, the hypothesis and the actual observed data of different categories are used to calculate the value of Kappa. What for? Using Kappa instead of Kendall, Kendall gives a coefficient (values ranging from 0 to 1) but very insignificant [0.4874]. That is to say Kendall says he is by chance alone Q . 166 Kappa is used to draw conclusions about the strength of a measurement system when attribute data is used. The Kendall coefficient is used to deduce the strength of the measurement system when ordinal attribute data are used. What are the likely errors if you used the Kappa value to draw conclusions about an ordinlat attribute data? Therefore, the value of kappa is only useful if we need to get exclusions from data that do not have the grades of the category to ensure: (Kappa`s negative values indicate very poor reliability inter-rater) p-values >0.6 said (with 5% risk of type 1 error) not rejecting the zero assumption that the agreement is due to chance alone.
Notice Agreement is close to 50%; thanks to Bernoulli`s random number option in Minitab.