# Sweep the Parameter and Find the Flat Region
## Claim
Sweeping a parameter across its range to find where the output stops changing beats reasoning about which value should be correct.
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## Scope & conditions
- The flat region is the useful finding — it tells you the setting does not matter there, which is more actionable than a single tuned value.
- Requires the sweep to be cheap relative to the decision; where each run is expensive, reasoning first to narrow the range is the right order.
- Guards against the specific failure of adopting a plausible default and never testing whether it mattered.
- Applies to effort settings, chunk sizes, timeouts, retry counts — anywhere a number was picked once and inherited since.
## Evidence
From Anthropic's guidance on reducing cost and improving performance with the Claude platform: parameter sweeps are the recommended method over reasoning about defaults.
## Links
- [[A Specific Number Borrows Authority From a Measurement It Never Had]] — the defect this practice fixes — an untested default that reads as tuned
- [[Effort Is a Cost-Quality Dial That Subsumes Prompt Complexity]] — the specific parameter where the sweep pays off most
- [[3. Resources/MOCs/AI Cost & Tokenomics MOC]] — the tokenomics thread on tuning method.