Recent reasoning-focused large language models (LLMs) (e.g., GPT-o1 and DeepSeek-R1) combine chain-of-thought prompting with reinforcement learning to generate explicit, multi-step derivations. However, their practical advantages over standard instruction-tuned models remain underexplored. In this article, we present a comprehensive empirical study to address these gaps. We compare reasoning-focused and non-reasoning LLMs across several critical dimensions: (1) their performance on mathematical and general reasoning benchmarks; (2) their generalization capabilities across 30 sub-disciplines spanning six scientific domains; (3) the qualitative and quantitative differences in their underlying solution processes; and (4) the impact of model compression via distillation on core reasoning capabilities. Crucially, to reliably conduct our in-depth process analysis, we address the critical issue of LLM-as-a-Judge reliability by proposing and validating a multi-level evaluation framework against human experts. Our experimental results demonstrate that reasoning-focused models significantly outperform non-reasoning counterparts on logic-intensive tasks such as mathematics and physics, while the latter remain competitive on factual or observational problems (e.g., biology, geography). Specifically, our validated process analysis reveals distinct styles: DeepSeek-R1 generates more elaborate reasoning processes, correlating with greater effectiveness on harder tasks, despite potential redundancy. In contrast, GPT-o1 exhibits greater conciseness and frequently presents solutions with superior clarity and efficiency, particularly on simpler problems, while struggling with complex scenarios. Additionally, reasoning capabilities can be partially preserved through distillation, with distilled reasoning models consistently outperforming their non-reasoning counterparts across all domains. These findings provide new insights into when and how explicit reasoning contributes to LLM performance, offering practical guidance for model development and deployment.

Pretrained language models (PLMs), especially large language models (LLMs) demonstrate impressive capabilities in open-ended text generation. While our statistical results show that LLMs often suffer from over-concentrated information, where the generated texts overly focus on the given prompt and fail to provide sufficient background and detailed information as humans do. To address this issue, we propose a dynamic knowledge-guided informative open-ended text generation approach, that utilizes a knowledge graph to help the model generate more contextually related entities and detailed facts. Specifically, we first employ a local knowledge filter to extract relevant knowledge from the comprehensive knowledge graph for a given topic sentence. Then we introduce a dynamic knowledge selector to predict the entity to be mentioned in the subsequent sentence. Finally, we utilize a knowledge-enhanced text generator to produce a more informative output. To evaluate the effectiveness of our approach, we evaluate the proposed approach in two scenarios: fine-tuning for small PLMs and prompt tuning for LLMs. Experimental results show that our approach could generate more informative texts than baselines.