Outcome: implement GroupKFold; name 3 leakage sources. Curated video (7:19, verified 2026-09-24 via yt-dlp): Stop User Leakage: Group Splits (Professor Py: AI Foundations) Watch: https://www.youtube.com/watch?v=MnuSEB1Yihg Notes: User-level leakage: same entity must never span train/test. Group splits (sklearn GroupKFold / GroupShuffleSplit) as the fix. Lab: implement GroupKFold; name 3 leakage sources (entity overlap, temporal leak, target-derived features). Key moments: No chapter markers on source; key beats: leakage demo, group-split fix, GroupKFold usage.
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Leakage Control + GroupKFold Lab Stop User Leakage: Group Splits (Professor Py: AI Foundations) Watch: https://www.youtube.com/watch?v=MnuSEB1Yihg (7:19)
User-level leakage: same entity must never span train/test. Group splits (sklearn GroupKFold / GroupShuffleSplit) as the fix. Lab: implement GroupKFold; name 3 leakage sources (entity overlap, temporal leak, target-derived features).
No chapter markers on source; key beats: leakage demo, group-split fix, GroupKFold usage.