The aim of this study is to introduce weighted inter-rater agreement statistics used in ordinal scales, compare weighted agreement statistics along with the Spearman correlation coefficient and revealtheir status of being affected by the sample size and number of categories. For this purpose, data for
different sample sizes and number of categories were produced for the cases when there is no
relationship or when there is low, medium, or high relationship between the two raters, and the
aforementioned weighted agreement statistics were calculated. It can be said that Cohen’s kappa,
Scott’s π, and Krippendorff’s alpha coefficients provide similar results with the correlation
coefficients, and they get values very close to the correlation coefficient value in the B-P agreement
statistics. However, it can be said that Gwet’s AC2 statistic, especially for a category number of 3,
differs from the correlation coefficient value in cases where there is no/low correlation between the
raters, and a moderate level of agreement can be mentioned between the raters, albeit by chance.
While investigating the agreement between two raters in ordinal scales, it is recommended to be
careful in cases when only the number of categories is three and to use Gwet’s AC2 agreement
statistics. In other cases, it can be said that the concepts of agreement and relationship can be used
interchangeably with peace of mind.