Detecting, Decomposing, and Stress-Testing Temporal Change in Repeated Decision Systems R package DecisionDrift version 0.1.0 Tools for detecting, decomposing, and stress-testing temporal drift in repeated binary decision systems. Complements the 'decisionpaths' package by shifting focus from path construction to system-level change over time. Implements five core analytic modules: (1) prevalence drift — did the overall decision rate change over time?; (2) transition drift — did the probability of switching or persisting change?; (3) entropy and stability trends — did path complexity evolve?; (4) group-differential drift — did the system drift differently across subgroups?; (5) change-point and regime-shift detection — did the system change abruptly after a policy or model update? Additionally provides a robustness module for testing stability of drift conclusions across analytic choices, and a sensitivity module for probing vulnerability to data problems including missingness, miscoding, and threshold shifts. Defines four original drift indices: the Decision Drift Index (DDI), Transition Drift Index (TDI), Group Differential Drift (GDD), and Cumulative Drift Burden (CDB). Applications include algorithmic audit, AI governance, education, health, and organisational research. Software Depends: R (>= 4.1.0) Imports: cli (>= 3.0.0), rlang (>= 0.4.0), stats, tibble (>= 3.0.0) Suggests: decisionpaths, ggplot2 (>= 3.3.0), knitr, patchwork, rmarkdown, testthat (>= 3.0.0) Subir Hait <haitsubi@msu.edu> Comprehensive R Archive Network (CRAN) Subir Hait [aut, cre] (ORCID: <https://orcid.org/0009-0004-9871-9677>) MIT + file LICENSE (https://CRAN.R-project.org/package=DecisionDrift/LICENSE) 2026-04-16 application/tgz https://CRAN.R-project.org/package=DecisionDrift doi:10.32614/CRAN.package.DecisionDrift en-GB