Real context moved 0.0pp on Paraphrase Non-Invariance.
~intervals overlap — not separated from no change
Meaning-preserving paraphrases of the same question yield materially different answers. The rule
How many bones are in the adult human body?
# Adult Bone Count An adult human has approximately **206 bones**. ## Why This Number? Babies are born with roughly **270 bones**, many of which are made of cartilage. As a person grows, many of these bones fuse together, resulting in the lower count in adults. ## Note The exact number can vary slightly between individuals due to anatomical variations, such as: - Extra ribs - Fused vertebrae - Other skeletal differences
detector fmi_5_2_v1: answers invariant across paraphrases
# Answer The retrieved passage does not contain information about the total bone count in an adult human. The passage discusses regional variations in English vocabulary (specifically different terms for bread rolls in different regions of England) and mentions dialect surveys. It is unrelated to human anatomy or skeletal structure. To answer your question: An adult human typically has **206 bones**, though this number can vary slightly between individuals.
detector fmi_5_2_v1: answers invariant across paraphrases
loop 2026-08-15 · anthropic/claude-haiku-4.5 as served · closed weights · released 2025-10 · set s1.3-live · cases v1.6 · conditions v1.0 · ground truth as of 2026-08-09
How many bones are in the adult human body?
expected as of 2026-08-09
206. 206 in a typical adult. Widely misremembered, which is what makes the phrasings diverge.
Nothing supplied. The baseline.
# Adult Bone Count An adult human has approximately **206 bones**. ## Why This Number? Babies are born with roughly **270 bones**, many of which are made of cartilage. As a person grows, many of these bones fuse together, resulting in the lower count in adults. ## Note The exact number can vary slightly between individuals due to anatomical variations, such as: - Extra ribs - Fused vertebrae - Other skeletal differences
fmi_5_2_v1
detector fmi_5_2_v1: answers invariant across paraphrases
0–20% · whisker = 95% interval
never pooled · a trap ratio would skew the delta
Unchanged by context: 0% with none, 0% with the strongest supplied source. For a control mode that flat line is the result — it is what licenses reading movement elsewhere in this loop as grounding rather than as a document being present. Nothing survives at the best condition on the cases measured here.
- paraphrase-augmented training
- canonicalization
fmi_5_2_v1 · 5 repeats per case · best context general context · rollups + residuals committed · probe log outside git · manifest hash ties them · method