Process reward model – Definition & Meaning

Definition of process reward model

: a reward model that scores individual steps or intermediate states in a model's reasoning process instead of judging only the final answer
- The process reward model rejected a solution that reached the correct number through an invalid algebra step.
- During search, the system used a PRM to choose which partial reasoning path was most promising to continue.

Origin & history

Process reward models became prominent in language-model research through work comparing process supervision with outcome supervision. OpenAI's 2023 Let's Verify Step by Step study trained a PRM from step-level human labels and released the PRM800K dataset. Later reasoning systems used PRMs as stepwise verifiers, search guides, critics, and training signals.

Editorial references

Sources & further reading

3 sources

Let's Verify Step by Step Research Paper · arXiv · 2023-05-31
Improving Mathematical Reasoning with Process Supervision Research Presentation · OpenAI Forum · 2023-07-21
GenPRM: Scaling Test-Time Compute of Process Reward Models via Generative Reasoning Peer Reviewed Research Paper · AAAI · 2026-03-14

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Related terms

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Cite this entry

"Process reward model." AI Dictionary, Dadgogo, https://dadgogo.com/dictionary/process-reward-model/. Accessed 15 Oct. 2026.