Intermediate level · Module 3: Building Image and Text Data Sets · Lesson 2 of 3
Label Quality and Leakage-Free Splits
Measure label agreement, find label errors and split data so evaluation is honest.
In this lesson you will
- Measure label agreement and correct errors
- Split data without near-duplicate leakage
Key concepts
inter-annotator agreementlabel noisenear-duplicate imagesgroup-based splitting
The lesson
Have a sample labelled twice and measure agreement; low agreement means the guidelines are unclear. Review images the model gets confidently wrong — many turn out to be label errors.
Photos taken seconds apart are near-duplicates. If one is in training and another in testing, the test score is inflated.
Split by group — the photo session, the package or the person who took it — so related images stay in the same split.
Step by step
- Double-label a sample and measure agreement.
- Fix the guideline problems found.
- Find near-duplicates with image hashing.
- Split by photo session.
Practice activity
Produce quality metrics and leakage-free splits for the project data.
Expected result: Agreement figures, corrected labels and group-based splits.
Check your understanding
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Why do near-duplicates across splits inflate results?
Show answer
The model is tested on images almost identical to ones it trained on.
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What does low labeller agreement suggest?
Show answer
Unclear guidelines or genuinely ambiguous cases.
Taught live by an instructor — online or in person. Free course lessons are for self-study and do not lead to a certificate — see registration options.