A Tool for Agreement and Alignment Analysis in Binary Rating Tasks: The R Package scindex

scindex is an R package for analysing inter-rater reliability in binary classification tasks. The package computes Cohen’s κ and Fleiss’ κ and, when ground-truth labels are available, estimates signal detection theory parameters, including sensitivity, specificity, and decision thresholds. It also implements the Strategic Convergence Index (SCI), a measure of convergence in raters’ response criteria.