Non-determinism
The property that allows apparently identical requests to produce different outputs, whether correct or incorrect.
Illustrative conversation
- Why did the second run choose a different valid refactor?
- The model is non-deterministic, so both runs could follow different high-probability paths from the same context.
Definition
Non-determinism means repeated model requests can produce different outputs even when their visible inputs appear identical. Generation samples from possible next tokens, and provider-side implementation details may also vary; lowering temperature can make output more focused but does not create a universal reproducibility guarantee. Agent tests should therefore validate required outcomes and constraints, not exact prose alone.
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