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Influences

The approach in this repository builds on Chip Huyen's books — AI Engineering: Building Applications with Foundation Models (O'Reilly, 2025) and Designing Machine Learning Systems (O'Reilly, 2022). Their framing — that evaluation is engineering work on your data, that a model is chosen on a private leaderboard rather than a public one, that the dataset is a design decision, and that every experiment must be tracked and versioned — is the foundation this harness was built on. If the method here is useful to you, read them.

Below, each idea this project relies on, where her books set it out, and what this repository added. The book references are to her own published chapter summaries (AI Engineering, Designing ML Systems), so each line can be checked.

Idea in this project In her books What this repository adds
Build your own evaluation, on your own data — the reason the harness exists, and the message of Use it AI Engineering ch. 4: public benchmarks rarely identify the best model for a specific application, and are likely contaminated; choosing a model is building a private leaderboard; the lack of a reliable evaluation pipeline is one of the biggest blockers to adoption A drop-in harness for that private leaderboard, and five worked examples showing what a public leaderboard would have hidden
Silver is not gold — model-written references rank, person-written ones judge AI Engineering ch. 3: AI-as-a-judge evaluation is subjective, depends on the judge, is not comparable across judges, and should be supplemented with exact or human evaluation Reference tiers recorded on every run; gold preferred automatically; silver-calibrate; rescore --reference-id to move runs onto gold for $0
No single score — combine methods AI Engineering ch. 4: no perfect evaluation method exists; combining methods mitigates their limits Quality, billed cost and latency side by side in every comparison; standard metrics reported beside this repo's own
The dataset is a design decision — small, high-quality gold; size measured, not assumed AI Engineering ch. 8: quality, coverage and quantity; a small amount of high-quality data can beat a large amount of noisy data; annotation guidelines are hard; performance-gain curves across dataset sizes Datasets frozen by content hash and re-checked on every use; rank-stability to measure how many items a ranking needs
Sampling, and the population a sample claims to represent Designing ML Systems ch. 4 (sampling methods) and ch. 8 (data distribution shifts) The calibration rows that caught this repository's own all-CNN sample, and the DailyMail slice that tested whether findings travel
Labels are expensive — start without perfect ones Designing ML Systems ch. 4: hand labels are expensive and slow; alternatives to them Silver references by default, gold where a person has checked, and the tier stated wherever a number is published
Baselines Designing ML Systems ch. 6: evaluation metrics don't mean much without a baseline to compare them to Floor arms in every experiment (lead-3, keyword rules, a constant, random rankings); promoted baselines recorded with their reason
Track and version every experiment Designing ML Systems ch. 6: intensive tracking and versioning of experiments, automated by tooling A fingerprint per run — data, prompt, scorer, upstream model, libraries, commit — and refusals when it cannot be trusted (dirty tree, unknown build, two runs of one config)

Other foundations

  • Testing separations, not reading rank order — the statistics are older than any of this: Holm (1979) for multiple comparisons, Demšar (2006) for comparing systems over many items, Dror et al. (2018) for significance testing in NLP. Full references in REFERENCE and papers.
  • Calibrating an instrument against published results — standard reproduction practice; each benchmark's original paper is the published value (PROTOCOL).
  • Production rules — Martin Zinkevich, Rules of Machine Learning (Google): design and implement your metrics first. Breck et al., The ML Test Score (2017): tests for data, models and infrastructure.
  • Offline gains are not real gains — Bernardi et al., 150 Successful Machine Learning Models (KDD 2019, Booking.com).

More, curated by Chip Huyen: huyenchip.com/mlops.