Finalized Ridge/Lasso thesis notebook and diagnostics
- Day: 2026-06-10
- Time: 11:45 to 12:35
- Project: Dev
- Workspace: WP 2: Operational
- Status: Completed
- Priority: MEDIUM
- Assignee: Matías Nehuen Iglesias
- Tags: Ridge, Lasso, Regularization, Thesis, Notebook, Diagnostics
Description
Session Goal
Refine the thesis regularization chapter by turning Ridge and Lasso into a diagnostic scaffold rather than a pure model-selection contest, while also finalizing a notebook workflow that can be executed from existing artifacts.
Key Activities
- Reframed Ridge/Lasso results as evidence about shrinkage, sparsity, coefficient compression, and bias-variance tradeoffs, not as a prediction breakthrough over OLS.
- Audited the preprocessing pipeline to assess whether the current design is suitable for interpreting regularization paths.
- Identified a methodological gap: numeric features are standardized, but one-hot categorical dummies are not, which affects coefficient comparability.
- Proposed a standardized-design variant and clarified collinearity / drop-first implications for interpretation.
- Designed a thesis-ready notebook structure using existing run artifacts: setup, CV summaries, coefficient-path interpretation, tails, and approximate bias-variance proxies.
- Defined a reproducible artifact audit plan to inspect configs, schemas, metrics, CV outputs, coefficient artifacts, and missing diagnostics.
- Added book-style visualization logic using relative coefficient norms and normalized CV error proxies to make the regularization story more interpretable.
- Finalized the notebook iteration with exported figures and tables, and preserved intermediate tables for continued review.
Achievements
- Established a coherent thesis narrative: regularization is useful as a diagnostic lens, but the best Ridge/Lasso settings remain close to OLS in predictive performance.
- Clarified that mild sparsity can be obtained with limited performance loss, supporting a parsimonious interpretation.
- Flagged P09 categories as influential enough to justify a category-level audit and sensitivity analysis.
- Documented the notebook/output structure and the expected artifact locations for reproducible analysis.
- Identified backend gaps that may require future implementation, especially coefficient-path exports by alpha and compression diagnostics.
Pending Tasks
- Run the proposed P09 sensitivity / category-level audit.
- Regenerate any missing compression-distribution CSV if needed.
- Decide whether to implement backend support for coefficient-path exports and additional diagnostics.
- Apply notebook figure fixes and thesis revisions based on the new diagnostic framing.
Evidence
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- event_ids: []