Predicting Performance of Symbolic and Prompt Programs with Examples
Summary
This study introduces a Bayesian framework for predicting the performance of both symbolic (e.g., Python) and prompt (LLM-executed) programs using a simple coin-flip model. Researchers found that symbolic programs exhibit an "all-or-nothing" performance prior, meaning a few successful tests reliably indicate high performance. In contrast, prompt programs have a diffuse prior with many "nearly-correct" instances, making their performance prediction uncertain with limited examples. To address this, the paper proposes RAP (Retrieved Approximate Prior), a method that constructs a domain-specific prior for prompt programs by retrieving similar tasks and programs from a corpus. RAP then updates this prior with observed test outcomes to predict performance, demonstrating superior accuracy over baselines and improved performance with larger corpora.
Key takeaway
For Machine Learning Engineers deploying LLM-based prompt programs, recognize that a few successful test cases do not reliably predict real-world performance due to their diffuse "nearly-correct" prior. Instead, consider implementing a system like RAP to construct a more accurate, domain-specific performance prior by leveraging existing task and prompt corpora. This approach provides a more calibrated confidence score for deployment decisions, especially when test data is limited, reducing unexpected failures.
Key insights
Symbolic programs are "all-or-nothing" in performance, while prompt programs are "diffuse" and less predictable.
Principles
- Symbolic program performance prior is sharply bimodal (0.0 or 1.0).
- Prompt program performance prior is diffuse, with many "nearly-correct" programs.
- Few test cases certify symbolic programs, but not prompt programs.
Method
RAP constructs a prior for prompt programs by retrieving behaviorally similar tasks and programs from a corpus, forming a Beta mixture, and updating it with observed test outcomes.
In practice
- Use more test cases for prompt programs than symbolic programs.
- Build task-specific priors for better LLM performance prediction.
- Leverage existing code/prompt corpora to inform new program reliability.
Topics
- LLM Performance Prediction
- Prompt Program Reliability
- Symbolic Program Verification
- Bayesian Performance Modeling
- Retrieval Approximated Prior
- Empirical Performance Priors
Best for: AI Engineer, NLP Engineer, Research Scientist, AI Scientist, Machine Learning Engineer, Prompt Engineer
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Editorial summary, takeaway, and curation by AIssential. Original article published by cs.LG updates on arXiv.org.