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Guide: Interpreting Model Results

This guide explains how to read AMMM V2 outputs by stage, and in what order to trust them.

  • Which files matter most in each stage folder
  • Convergence, calibration, and Pareto checks
  • Decomposition and optimisation interpretation caveats

Before interpreting channel insights, inspect 50_diagnostics/:

  • convergence_report.json (converged)
  • calibration_report.json (well_calibrated)
  • pareto_k_summary.json (ok)

Thresholds used in current diagnostics:

  • R-hat warn at > 1.01, fail at > 1.05
  • ESS threshold >= 100 × n_chains (bulk and tail)
  • Divergences warn at 1+, fail at 10+
  • Pareto k marginal (0.5, 0.7], poor > 0.7

If diagnostics_gating: strict and convergence fails, the workflow can halt before downstream stages.

  • model.nc: posterior and related groups in InferenceData
  • model_summary.csv: posterior summaries (including R-hat and ESS)
  • model_trace.png: trace diagnostics
  • posterior_forest.png, posterior_forest_all_params.png
  • prior_posterior_comparison.png
  • model_fit_predictions.png: actuals vs posterior predictions
  • model_fit_metrics.csv: fit metrics
  • posterior_predictive_check.png: distribution-level PPC

Interpretation:

  • Look for systematic bias in fit residuals.
  • Check uncertainty width, not just point fit.

Key files:

  • all_decomp.csv
  • waterfall_plot_components_decomposition.png
  • media_contribution_mean.png, media_contribution_median.png
  • media_contribution_per_spend.csv
  • media_cost_per_revenue_unit.csv

Key files:

  • response_curves.png
  • all_response_curves.csv
  • response_curve_fit_combined.csv

Interpretation:

  • Use HDI ranges (94% default) rather than single-point claims.
  • Treat contribution/ROI rankings as posterior distributions, not fixed truths.
  • optimization_results.csv
  • budget_optimisation.png
  • budget_scenario_results.csv
  • scenario comparison plots
  • multiperiod_optimization_results.csv and related multi-period plots

Interpretation:

  • Optimisation quality depends on model adequacy and calibration.
  • Compare recommended allocations to operational constraints before actioning.
  • ammm_report.md
  • business_report.md
  • agentic_report.md (when enabled)
  • llm_interpretations.json

Use reports as summaries of artefacts, not as replacements for diagnostics.

  1. 10_pre_diagnostics/: stationarity/VIF/prior predictive.
  2. 50_diagnostics/: convergence, calibration, Pareto k.
  3. 30_model_assessment/: fit and PPC.
  4. 40_decomposition/ and 60_response_curves/: channel interpretation.
  5. 70_optimisation/: planning outputs.

Important caveat:

  • Diagnostic adequacy improves reliability, but does not prove causal validity.