NeuroComparatives: Neuro-Symbolic Distillation of Comparative Knowledge

Abstract

Comparative knowledge (e.g., steel is stronger and heavier than styrofoam) is an essential component of our world knowledge, yet understudied in prior literature. In this paper, we study the task of comparative knowledge acquisition, motivated by the dramatic improvements in the capabilities of extreme-scale language models like GPT-4, which have fueled efforts towards harvesting their knowledge into knowledge bases. While acquisition of such comparative knowledge is much easier from models like GPT-4, compared to their considerably smaller and weaker counterparts such as GPT-2, not even the most powerful models are exempt from making errors. We thus ask: to what extent are models at different scales able to generate valid and diverse comparative knowledge? We introduce NeuroComparatives, a novel framework for comparative knowledge distillation overgenerated from language models such as GPT-variants and Llama, followed by stringent filtering of the generated knowledge. Our framework acquires comparative knowledge between everyday objects, producing a corpus of up to 8.8M comparisons over 1.74M entity pairs - 10X larger and 30% more diverse than existing resources. Moreover, human evaluations show that NeuroComparatives outperform existing resources (up to 32% absolute improvement). We also demonstrate the utility of our distilled NeuroComparatives on three downstream tasks. Our results show that neuro-symbolic manipulation of smaller models offer complementary benefits to the currently dominant practice of prompting extreme-scale language models for knowledge distillation