Description: The Kappa coefficient is a statistical measure that evaluates the agreement between two or more raters or classifications, correcting for the agreement that could occur by chance. This coefficient is primarily used in research studies where it is necessary to measure the reliability of classifications, especially in contexts where qualitative categories are handled. Its value ranges from -1 to 1, where 1 indicates perfect agreement, 0 suggests that the agreement is equivalent to chance, and negative values indicate disagreement. The Kappa coefficient is particularly relevant in the analysis of various systems where the consistency of decisions made by different entities is evaluated, such as in surveys, clinical assessments, and machine learning classifications. In these contexts, the coefficient can help determine the reliability of classifications and the validity of decisions, providing a quantitative metric that can be used to enhance trust in the evaluation process. Its application is crucial, as the integrity of the system depends on the ability of entities to reach a consensus on classifications, and the Kappa coefficient offers a way to measure how aligned these entities are in their decisions.
