Self-Taught Optimizer (STOP)

Seed improver: A "seed improver" program first improves an input program to return the best solution found - a self-improvement scaffold built on GPT-4.

Recursive improvement: The seed improver is itself tasked with improving itself, producing the first concrete demonstration of recursive self-improvement in LLM code generation.

GPT-4 capable: Shows that GPT-4 models can write code that modifies itself iteratively, producing measurably better scaffolds than the initial seed.

Foundational work: An early, influential demonstration of the LLM-as-code-modifier pattern that would reappear across 2024 in agent and tool-use research.