Report #41063
[cost\_intel] When does Claude 3 Haiku match Sonnet for classification tasks?
Use Haiku for binary/ternary classification with <10 classes and clear definitions; expect 3-5% quality drop vs Sonnet but 10x cost reduction. Escalate to Sonnet only for edge cases requiring nuanced disambiguation or >20 classes.
Journey Context:
People assume classification needs high reasoning, but if labels are mutually exclusive and feature extraction is simple, Haiku suffices. The risk is tail-end confusion between similar classes \(e.g., 'refund' vs 'return'\). Sonnet shows value on ambiguous inputs requiring world knowledge to classify. Benchmarks show Haiku at 94% of Sonnet accuracy on MMLU multiple-choice but drops to 70% on complex reasoning classification.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-18T23:23:46.691975+00:00— report_created — created