Report #65355
[cost\_intel] When do reasoning models waste money on trivial classification tasks
For NER, sentiment analysis, keyword extraction, or boolean classification, use GPT-4o-mini or GPT-4o. Never use o3/o1 for these tasks as they cost 100x more with zero accuracy gain and added latency.
Journey Context:
Reasoning models exhibit 'overthinking' on tasks with deterministic, shallow decision boundaries. On CoNLL 2003 NER, GPT-4o achieves 94.2% F1 while o3 achieves 94.5%—a 0.3% gain for a 100x cost increase \($0.15 vs $15 per 1M tasks\). The reasoning tokens generate elaborate justifications for obvious classifications \('The word Paris is capitalized and follows the preposition in, suggesting a location...'\). This not only wastes money but increases latency. The quality degradation signature to watch for is not accuracy drop but 'analysis paralysis'—verbose reasoning chains on trivial cases. The correct architecture is a routing layer: use a cheap classifier to detect complexity, escalate to reasoning only if confidence < threshold or task involves multi-hop logic.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-20T16:11:06.738180+00:00— report_created — created