Knowledge or Reasoning
Free while signed in. Answers cite the passages they came from.
Introduces a fine-grained evaluation framework to dissect LLM thinking into two components: knowledge correctness and reasoning informativeness, measured via Knowledge Index (KI) and Information Gain (InfoGain), respectively. The authors apply this framework to evaluate how reasoning transfers across domains, particularly medical and mathematical, using Qwen2.5-7B and its DeepSeek-R1-distilled variant trained via SFT and RL. Key findings include:
SFT improves knowledge but can harm reasoning: Supervised fine-tuning improves factual accuracy (e.g., 6.2% KI gain in medical tasks), but often leads to verbose or redundant reasoning that reduces InfoGain by 38.9% on average, compared to the base model.
RL boosts both reasoning and knowledge in medical settings: Reinforcement learning enhances reasoning clarity and prunes incorrect knowledge, leading to a 12.4-point average gain in KI. It improves inference by guiding models toward more factually sound reasoning paths.
Domain matters: While math tasks benefit more from reasoning (higher InfoGain), medical tasks rely heavily on domain knowledge (higher KI). In fact, KI shows a stronger correlation (0.998) with task accuracy than InfoGain (0.698) in medical benchmarks.
Base models outperform R1-distilled versions in medicine: Qwen-Base consistently outperforms DeepSeek-R1-distilled models across accuracy, InfoGain, and KI. The R1-distilled model struggles with medical adaptation, likely due to pretraining bias toward math/code domains
Get next week’s papers.
The same picks and the same summaries, in your inbox. Free, and 176 issues deep.
Subscribe on Substack