When calculating the percentage agreement, you must determine the percentage of the difference between two digits. This value can be useful if you want to show the difference between two percentage numbers. Scientists can use the two-digit percentage agreement to show the percentage of the relationship between the different results. When calculating the percentage difference, you have to take the difference in values, divide it by the average of the two values, and then multiply that number of times 100. To calculate pe (the probability of random match), we find that: Cohenkappa coefficient () is a statistic that is used to measure inter-rater reliability (and also intra-rater reliability) for qualitative elements (category). [1] It is generally accepted that this is a more robust indicator than a simple percentage of the agreement calculation, since the possibility of a random agreement is taken into account. There are controversies around Cohens Kappa because of the difficulty of interpreting the indications of the agreement. Some researchers have suggested that it is easier, conceptually, to assess differences of opinion between objects. [2] For more details, see Restrictions. The basic measure for Inter-Rater`s reliability is a percentage agreement between advisors. The field in which you work determines the acceptable level of agreement.

If it is a sporting competition, you can accept a 60% agreement to nominate a winner. However, if you look at the data from oncologists who choose to take a treatment, you need a much higher agreement – more than 90%. In general, more than 75% are considered acceptable in most areas. A case that is sometimes considered a problem with Cohen`s Kappa occurs when comparing the Kappa, which was calculated for two pairs with the two advisors in each pair that have the same percentage agree, but one pair gives a similar number of reviews in each class, while the other pair gives a very different number of reviews in each class. [7] (In the following cases, there is a similar number of evaluations in each class.[7] , in the first case, note 70 votes in for and 30 against, but these numbers are reversed in the second case.) For example, in the following two cases, there is an equal agreement between A and B (60 out of 100 in both cases) with respect to matching in each class, so we expect Cohens Kappa`s relative values to reflect that. However, calculate Kappa Cohens for each: Suppose you analyze data related to a group of 50 people applying for a grant. Each grant proposal was read by two readers, and each reader said “yes” or “no” to the proposal.