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promptbrittle
confirmedPython · CPUModel behavior & reasoningJuly 5, 2026
the question
How much does prompt format alone -- not content -- move accuracy?
what came out
On GSM8K, semantically-equivalent formats swing accuracy 25 points (0.42 to 0.68) on the same questions (McNemar p 0.006), with reasoning elicitation the biggest lever. The wording is a hyperparameter.
method & receipts
- Result: confirmed
- Reproducible — one script re-runs the whole thing from scratch.
- Machine-readable claims — every reported number, in a checkable file.
- Tested — a correctness/benchmark suite ships alongside the code.
→ read the code and re-run it
github.com/v-code01/promptbrittle