HGB benchmark sweep and artifact planning
- Day: 2026-05-17
- Time: 11:10 to 11:20
- Project: Dev
- Workspace: WP 2: Operational
- Status: Completed
- Priority: MEDIUM
- Assignee: Matías Nehuen Iglesias
- Tags: Histgradientboosting, Hyperparameter-Sweep, Cross-Validation, Overfitting, Artifact, Ml-Experiment
Description
Session Goal
Interpret recent HistGradientBoosting regression sweeps, identify the practical performance ceiling, and decide what to optimize next. A secondary thread defined a deterministic training-frame artifact to support leakage checks and reproducible inspection.
Key Activities
- Reviewed learning-rate / iteration sweeps for HistGradientBoosting and concluded validation performance plateaus around CV R2 ≈ 0.545-0.547.
- Compared the effect of L2 regularization and found it has negligible impact on CV R2, train R2, or the overfit gap in the tested region.
- Consolidated the min_samples_leaf sweep into a defendable benchmark configuration, separating a fast default from a more expensive best-observed candidate.
- Drafted a run-local training-frame sample artifact: deterministic CSV + metadata capture of the exact training frame used before fitting, with run-manifest registration and tests to prevent leakage or duplicated per-model artifacts.
Achievements
- Established that further boosting mainly increases overfitting rather than validation gain, implying a predictive ceiling near the observed CV R2 plateau.
- Narrowed future hyperparameter search priorities to learning_rate, max_iter, and max_leaf_nodes, while treating L2 regularization as secondary.
- Clarified the next research direction as feature/target/error analysis instead of brute-force model scaling.
- Defined artifact requirements for reproducible inspection, including forbidden-column checks and a clean separation from prediction/runtime outputs.
Pending Tasks
- Run a smaller confirmatory experiment focused on the useful region of learning_rate, iterations, and leaf count.
- Implement and test the training-frame sample artifact with CSV/metadata outputs and manifest registration.
- Perform feature, target, and residual/error analysis to identify whether gains now depend more on data/feature engineering than model complexity.
Evidence
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- event_ids: []