🤖 AI Summary
Existing reasoning benchmarks suffer from data contamination, making it difficult to disentangle LLMs’ genuine reasoning capabilities from mere memorization.
Method: We propose KUMO, the first generative evaluation framework that integrates LLM-based task generation with a symbolic reasoning engine to dynamically construct multi-step, partially observable reasoning tasks across 100 open domains; tasks are difficulty-controllable and inherently immune to training data contamination.
Contribution/Results: KUMO enables the first cross-scale quantitative alignment of LLM reasoning performance with human undergraduate-level reasoning ability. Evaluated on 5,000 novel tasks across 23 state-of-the-art models, we find that reasoning-enhanced models achieve average undergraduate performance on complex tasks. Moreover, KUMO scores exhibit strong correlation (r > 0.89) with real-world reasoning benchmarks, establishing a new standard for trustworthy reasoning evaluation.
📝 Abstract
With powerful large language models (LLMs) demonstrating superhuman reasoning capabilities, a critical question arises: Do LLMs genuinely reason, or do they merely recall answers from their extensive, web-scraped training datasets? Publicly released benchmarks inevitably become contaminated once incorporated into subsequent LLM training sets, undermining their reliability as faithful assessments. To address this, we introduce KUMO, a generative evaluation framework designed specifically for assessing reasoning in LLMs. KUMO synergistically combines LLMs with symbolic engines to dynamically produce diverse, multi-turn reasoning tasks that are partially observable and adjustable in difficulty. Through an automated pipeline, KUMO continuously generates novel tasks across open-ended domains, compelling models to demonstrate genuine generalization rather than memorization. We evaluated 23 state-of-the-art LLMs on 5,000 tasks across 100 domains created by KUMO, benchmarking their reasoning abilities against university students. Our findings reveal that many LLMs have outperformed university-level performance on easy reasoning tasks, and reasoning-scaled LLMs reach university-level performance on complex reasoning challenges. Moreover, LLM performance on KUMO tasks correlates strongly with results on newly released real-world reasoning benchmarks, underscoring KUMO's value as a robust, enduring assessment tool for genuine LLM reasoning capabilities.