Year: 2026
Type: conference-paper
Abstract: Model merging, typically on Instruct and Thinking models, has shown remarkable performance for efficient reasoning.In this paper, we systematically revisit the simplest merging method that interpolates two weights directly.Particularly, we observe that model interpolation follows a three-stage evolutionary paradigm with distinct behaviors on the reasoning trajectory.These dynamics provide a principled guide for navigating the performancecost trade-off.Empirical results demonstrate that a strategically interpolated model surprisingly surpasses sophisticated model merging baselines on both efficiency and effectiveness.We further validate our findings with extensive ablation studies on model layers, modules, and decoding strategies.Ultimately, this work demystifies model interpolation and offers a practical framework for crafting models with precisely targeted reasoning capabilities.Code is available at Github.
Institutions: University of Hong Kong, Tsinghua University
Language: English
Topic: Topic Modeling
Subfield: Artificial Intelligence
Field: Computer Science
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W7166864657