5-Fold Cross-Validation Score Iteration Curve
5-Fold CV Score
Regression Rejected
Kaggle Submission (0.789)
Autonomous Iteration Logs
Round 1 — Baseline Model
CV: 0.814
Trained baseline LightGBM model on raw numeric features. Established 5-fold cross-validation pipeline.
Round 2 — Feature Engineering (Title Extraction)
CV: 0.838 (+0.024)
Extracted honorific titles (Mr, Mrs, Miss, Master) from passenger names. CV score improved by +0.024.
Round 3 — Feature Engineering (Family Grouping)
CV: 0.849 (+0.011)
Combined SibSp and Parch into FamilySize and IsAlone flags. Hypothesis validated and committed.
Round 4 — High-Cardinality Ticket Frequency (Regressed)
CV: 0.799 (-0.050)
Attempted ticket prefix frequency encoding. CV score dropped by -0.050 due to noise overfitting. Automatically rolled back.
Round 5 — Hyperparameter Tuning & Cabin Deck Encoding
CV: 0.865 (+0.016)
Parsed Cabin deck letters and tuned num_leaves to 15. Achieved highest 5-fold CV score of 0.865. Submission file generated.