Lesson 1: Tracked experiments and honest comparisons
28 min read·
Module 6 · Lesson 1 · About 55 minutes · Needs: the time split, PR-AUC and search strategies (Module 3 lesson 3), seeds (Module 4 lesson 4), Git basics (Module 2 lesson 1) and the Kestrel data (course-guide/06).
The situation
Week 6 at Kestrel. Adaeze asks: "Can you reproduce last month's model exactly?" Nobody could rerun the spring prototype. Morag will pay for model v2 only if it beats v1 for sure, not on one lucky run.
Two things run through the lesson: a tracked run called v1 (Module 3's untuned LightGBM settings, seed 0), and parcel KP0104204 (simulated), collected at Dartford on 2 September 2026 and delivered late. v1 gives it 0.67; the tuned v2 gives it 0.748.