---
title: "Claude 3.5 Haiku"
type: "entity"
entity_kind: "concept"
status: "hub"
canonical_name: "Claude 3.5 Haiku"
aliases: []
first_seen: "2026-05-26T00:00:00.000Z"
writer_model: "claude-sonnet-5"
connects_to: ["On the Biology of a Large Language Model","attribution graphs","feature steering","Jack Lindsey"]
---


The specific Anthropic model version whose internals [[entity-on-the-biology-of-a-large-language-model]] traces via [[entity-attribution-graphs]] — every case study in the vault's interpretability cluster (poetry planning, two-hop reasoning, hallucination, a jailbreak, refusal, chain-of-thought faithfulness) is an experiment run on this one model, not a claim about Claude generally. Worth its own hub because the vault's claims about "how Claude thinks" are load-bearing on which Claude: mechanisms documented here (e.g. [[entity-feature-steering]] causally swapping a planned rhyme word) are demonstrated facts about this specific smaller, faster model and have not been shown to generalize to other Claude versions or architectures.

## References
- [[claim-biology-llm-dallas-texas-austin-genuine-two-step-reasoning]] · [[claim-biology-llm-poetry-planning-preactivates-rhyme-words]] · [[claim-biology-llm-poetry-steering-swaps-rhyme-or-abandons-it]] · [[claim-biology-llm-hallucination-is-known-entity-suppression-misfire]] · [[claim-biology-llm-jailbreak-assembles-bomb-by-parallel-letter-votes]] · [[claim-biology-llm-jailbreak-sentence-boundary-delays-not-triggers-refusal]] · [[claim-biology-llm-refusal-chain-is-harmful-request-recognition]] · [[cot-faithfulness-anthropic-biology]]
- [[entity-on-the-biology-of-a-large-language-model]] · [[entity-attribution-graphs]] · [[entity-jack-lindsey]] · [[entity-feature-steering]]