KappaWert

KappaWert, also known as Cohen's kappa or Cohen's kappa coefficient, is a statistic used to measure inter-rater reliability or agreement for categorical items. It quantifies the level of agreement between two raters (or one rater at two different times) who are classifying items into mutually exclusive categories.

The kappa coefficient corrects for the agreement that might occur by chance. A kappa value of 1 indicates perfect agreement. A kappa value of 0 indicates that the agreement is no better than what would be expected by chance. Negative kappa values suggest that the agreement is worse than chance, which is a rare occurrence and usually indicates a systematic disagreement.

The formula for kappa is (Po - Pe) / (1 - Pe), where Po is the observed proportion of agreement and Pe is the expected proportion of agreement by chance. The interpretation of kappa values can vary, but generally, values above 0.75 are considered excellent, 0.60 to 0.74 are considered good, 0.40 to 0.59 are considered fair, and below 0.40 are considered poor.

KappaWert is widely used in various fields, including psychology, medicine, and artificial intelligence, to assess the reliability of diagnostic tests, the consistency of expert judgments, and the performance of classification algorithms. It is particularly useful when dealing with subjective assessments where multiple observers are involved.