Preprint
Reinforcement Learning

Interpretable machine learning: Fundamental principles and 10 grand challenges

Cynthia Rudin, Chaofan Chen, Zhi Chen, Haiyang Huang, Lesia Semenova, Chudi Zhong
January 1, 2022Statistics Surveys987 citations

987

Citations

40

Influential Citations

Statistics Surveys

Venue

2022

Year

Abstract

Interpretability in machine learning (ML) is crucial for high stakes decisions and troubleshooting. In this work, we provide fundamental principles for interpretable ML, and dispel common misunderstandings that dilute the importance of this crucial topic. We also identify 10 technical challenge areas in interpretable machine learning and provide history and background on each problem. Some of these problems are classically important, and some are recent problems that have arisen in the last few years. These problems are: (1) Optimizing sparse logical models such as decision trees; (2) Optimization of scoring systems; (3) Placing constraints into generalized additive models to encourage sparsity and better interpretability; (4) Modern case-based reasoning, including neural networks and matching for causal inference; (5) Complete supervised disentanglement of neural networks; (6) Complete or even partial unsupervised disentanglement of neural networks; (7) Dimensionality reduction for data visualization; (8) Machine learning models that can incorporate physics and other generative or causal constraints; (9) Characterization of the “Rashomon set” of good models; and (10) Interpretable reinforcement learning. This survey is suitable as a starting point for statisticians and computer scientists interested in working in interpretable machine learning.

Analysis

Why This Paper Matters

Interpretability in machine learning is not merely a nice-to-have feature; it is a necessity for high-stakes decisions in healthcare, criminal justice, finance, and autonomous systems. This survey by Rudin et al. cuts through the noise by establishing fundamental principles and dispelling common misunderstandings that have diluted the importance of interpretability. By framing the field around 10 grand challenges, the paper provides a clear roadmap for researchers and practitioners, ensuring that efforts are directed toward problems that truly matter.

The timing of this work is critical. As deep learning models become more complex and pervasive, the gap between performance and interpretability widens. This survey bridges that gap by highlighting both classical problems (e.g., optimizing sparse logical models) and emerging ones (e.g., interpretable reinforcement learning). It serves as a wake-up call for the community to prioritize transparency and trustworthiness alongside accuracy.

Technical Contributions

The paper's main technical contribution is the identification and detailed exposition of 10 challenge areas:

  • Sparse logical models: Optimizing decision trees and rule lists for interpretability.
  • Scoring systems: Creating simple additive point-based models (e.g., risk scores).
  • Generalized additive models (GAMs): Enforcing sparsity and shape constraints for interpretability.
  • Case-based reasoning: Using prototypes and matching, including neural approaches.
  • Supervised disentanglement: Learning representations where each dimension corresponds to a meaningful concept.
  • Unsupervised disentanglement: Achieving interpretable latent factors without labels.
  • Dimensionality reduction: Visualization techniques that preserve interpretability.
  • Physics-informed ML: Incorporating causal and generative constraints.
  • Rashomon set: Characterizing the set of all good models, not just one.
  • Interpretable RL: Making reinforcement learning policies understandable.

Each challenge is grounded in historical context and current research, providing a springboard for future work.

Results

As a survey, the paper does not present new experimental results. Its value lies in the synthesis of existing knowledge and the articulation of open problems. The paper has garnered 987 citations, indicating its significant influence on the field.

Significance

This survey has become a cornerstone reference for interpretable ML research. By clearly defining principles and challenges, it has shaped the direction of subsequent work in explainable AI, causal inference, and human-centered machine learning. It emphasizes that interpretability should be a first-class citizen in model design, not an afterthought. The paper's impact extends beyond academia to industry, where regulatory and ethical demands increasingly require transparent AI systems.