Inter-rater reliability refers to the degree of agreement or consistency between different observers or raters when they assess the same phenomenon. It is crucial in research and assessments to ensure that results are not biased by individual interpretations. High inter-rater reliability indicates that different raters are likely to arrive at similar conclusions when evaluating the same data. To measure inter-rater reliability, researchers often use statistical methods, such as Cohen's kappa or intraclass correlation coefficient. These metrics help quantify the level of agreement and identify any discrepancies among raters. Ensuring strong inter-rater reliability enhances the credibility and validity of findings in various fields, including psychology, education, and healthcare.