Part V: Discovery Through Simulation and Optimization
Chapter 47: Experiment Registries and Scientific Provenance

Experiment Registries and Scientific Provenance

"I can reproduce any result in my lab, provided you give me the exact code, data, config, random seed, library versions, hardware specs, and phase of the moon from the original run. Otherwise, best of luck."

An Experiment Registry That Remembers Everything

Overview

Scientific discovery rests on reproducibility. If you cannot trace how a result was produced, you cannot verify it, extend it, or trust it. Yet the modern ML research workflow generates a torrent of artifacts: datasets, preprocessing scripts, model checkpoints, hyperparameter configurations, training logs, evaluation metrics, and deployment packages. Without a systematic registry that tracks what was produced, by whom, from what inputs, and under what conditions, even the researcher who ran the experiment may struggle to reproduce it a month later.

This chapter builds the infrastructure layer that makes every other chapter in this book reproducible. We start with the design of experiment registries: systems that assign stable identifiers to every artifact and record the relationships between them. We then formalize provenance using established standards (W3C PROV and OpenLineage) that make lineage information portable across tools and organizations. Finally, we construct a complete three-stage ML pipeline with full artifact tracing, hash verification, and reproducible regeneration from any point in the artifact graph.

The ideas here connect backward to the MLOps infrastructure of Chapter 22, where we introduced model lifecycle management, and to the automated experiment design of Chapter 46, which generates the experiments this chapter tracks. They connect forward to self-driving laboratories (Chapter 55), where provenance tracking becomes the audit trail that allows autonomous systems to operate safely, and to responsible discovery AI (Chapter 57), where reproducibility is an ethical obligation.

Prerequisites

Readers should be comfortable with Chapter 22: MLOps, LLMOps, and AgentOps for model lifecycle and deployment concepts, and with basic Git workflows. Familiarity with Chapter 6: Discovery System Architecture helps with understanding how the experiment registry integrates into the Discovery Workbench. No specialized database or systems engineering background is required.

Learning Outcomes

Sections

47.1 Registry Design and Artifact Versioning

Content-addressable storage, artifact taxonomy, and versioning strategies. Building a registry data model that tracks code, data, models, and configs with cryptographic hashes. Tools: Git, DVC, MLflow Model Registry, Docker.

47.2 Data Lineage and Provenance Standards

W3C PROV data model, OpenLineage specification, and run graphs. Formalizing the relationships between artifacts, processes, and agents. Building queryable provenance graphs that answer "how was this result produced?"

47.3 Building an Experiment Registry

Recipe: a three-stage ML pipeline with full artifact tracing, hash verification, and reproducible regeneration. Integrating MLflow tracking, DVC pipelines, and the Discovery Workbench into a provenance-complete system.

What's Next

With experiment registries providing the infrastructure for reproducible science, we shift from methodology to application. Chapter 48: Discovery AI for Biology and Medicine opens Part VI by applying every technique from Parts I through V to a specific scientific domain. The provenance tracking built in this chapter becomes especially critical in biomedical research, where regulatory requirements demand complete audit trails from raw data to published conclusions.

Bibliography

Standards and Specifications

Moreau, L. & Missier, P. (2013). PROV-DM: The PROV Data Model. W3C Recommendation.

The W3C standard for provenance interchange, defining entities, activities, and agents as the core primitives for describing how things were produced. The foundation for all provenance work in this chapter.

OpenLineage Project. (2021). OpenLineage Specification.

An open standard for runtime lineage collection across data pipelines. Provides the event-based model for capturing job runs, dataset inputs/outputs, and facets used in Section 47.2.

Tools and Platforms

Zaharia, M., Chen, A., Davidson, A., et al. (2018). Accelerating the machine learning lifecycle with MLflow. IEEE Data Engineering Bulletin, 41(4), 39-45.

Introduced MLflow's tracking, projects, models, and registry components. The primary experiment tracking platform used throughout this chapter.

Kuprieiev, R., Petrov, D., et al. (2021). DVC: Data Version Control. Git for Data & Models.

The data versioning tool that extends Git to handle large datasets and model files. Used in Section 47.1 for content-addressable artifact storage and in Section 47.3 for pipeline definitions.

Biewald, L. (2020). Experiment tracking with Weights and Biases. wandb.ai.

A cloud-native experiment tracking platform with artifact versioning, run comparison, and collaborative features. Compared with MLflow in Section 47.1.

Merkel, D. (2014). Docker: Lightweight Linux containers for consistent development and deployment. Linux Journal, 2014(239), 2.

Container technology for capturing the complete runtime environment. Used in Section 47.1 for environment reproducibility.

Research and Surveys

Baker, M. (2016). 1,500 scientists lift the lid on reproducibility. Nature, 533(7604), 452-454.

The landmark survey revealing that over 70% of researchers failed to reproduce another scientist's experiments, motivating the infrastructure this chapter builds.

Herschel, M., Diestelkämper, R., & Ben Lahmar, H. (2017). A survey on provenance: What for? What form? What from? VLDB Journal, 26(6), 881-906.

Comprehensive survey of provenance research across databases, workflows, and distributed systems. Provides the taxonomic framework for the provenance models in Section 47.2.

Pineau, J., et al. (2021). Improving reproducibility in machine learning research (A report from the NeurIPS 2019 Reproducibility Program). JMLR, 22(164), 1-20.

Documents the ML reproducibility crisis and proposes checklists and infrastructure requirements, many of which map directly to registry features built in this chapter.

Schelter, S., Boese, J.-H., Kirschnick, J., Klein, T., & Seufert, S. (2017). Automatically tracking metadata and provenance of machine learning experiments. NeurIPS MLSys Workshop.

Early work on automatic provenance capture for ML pipelines, introducing the concept of experiment management systems that inspired tools like MLflow and Neptune.

Data Lineage and Governance

Gulhane, V., et al. (2015). Web-scale data integration: You can afford to pay as you go. Proc. CIDR.

Discusses metadata management at scale, including lineage tracking across heterogeneous data sources, relevant to the multi-tool provenance integration in Section 47.3.

DAGsHub. (2021). DAGsHub: A platform for data science collaboration.

Combines Git, DVC, and MLflow into a collaborative platform for ML projects. Demonstrates the integration pattern used in Section 47.3's unified registry.