- Add "why measure retrieval quality" lead-in paragraph
- Expand ANN on first use; flag sparse vectors as out of scope
for layer 1 (they use exact matching)
- Add LLM-as-judge to layer-2 ground-truth options
- Break the Tooling bullet into per-layer recommendations: Web UI
for L1, ranx for L2, Ragas/Phoenix/DeepEval for L3
- Reorder Quality Metrics so layer 1 (ANN recall formula + exact
kNN equivalence) comes before the generic layer-2 relevance
metrics; trim a redundant sentence
- Add end-to-end answer quality as a distinct third layer in the
prose intro so it matches the ladder table's four rows
- Standardize vocabulary on "layer" (was mixing "level" in the
intro with "layer" everywhere else); update the section anchor
to #connecting-the-layers-in-practice in this file and the two
cross-linking tutorials
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
