DecisionDrift 0.1.0

Initial release

Core modules

• dd_build() — construct a drift_panel object from long-format panel data.
• dd_prevalence() — detect drift in decision rate; computes Decision Drift Index (DDI).
• dd_transition() — detect drift in transition structure; computes Transition Drift Index (TDI).
• dd_entropy_trend() — track rolling Shannon entropy and switching rate over time.
• dd_group_drift() — detect group-differential drift; computes Group Differential Drift (GDD).
• dd_changepoint() — change-point and regime-shift detection via CUSUM, segmented regression, and event alignment.

Summary indices

• dd_indices() — compute all four original drift indices in one call: DDI, TDI, GDD (Group Differential Drift), CDB (Cumulative Drift Burden).

Robustness & sensitivity

• dd_robustness() — test stability of drift conclusions across analytic choices (balanced panel, leave-one-period-out, leave-one-group-out, min_waves grid, bootstrap CI).
• dd_sensitivity() — probe vulnerability to data problems: decision miscoding, missing-wave attrition, threshold shifts, and subgroup composition shifts.

Flagship audit

• dd_audit() — integrated three-layer audit (detection → decomposition → stress-testing) with a single-call verdict.

Plotting

• S3 plot() methods for all module outputs.
• Multi-panel composite via plot.dd_audit() (requires patchwork).

Relationship to decisionpaths

• decisionpaths asks: What happened? (path construction, DRI, entropy, equity)
• DecisionDrift asks: Did the system change? (drift detection, decomposition, stress-testing)
• These packages form complementary layers of a longitudinal decision audit framework.