Large Language Models as Universal Predictors? An Empirical Study on Small Tabular Datasets
摘要
Large Language Models (LLMs) have demonstrated the potential to generalize across modalities and domains. With their in-context learning (ICL) capabilities, LLMs can perform predictive tasks over structured inputs without explicit fine-tuning. In this work, we investigate the empirical prediction capability of LLLMs on small-scale structured datasets for classification, regression and clustering tasks. We evaluate the performance of state-of-the-art LLMs (GPT, Gemini, DeepSeek) under few-shot prompting and compare them against machine learning (ML) baselines, including tabular foundation models (TFMs). Our results show that LLMs achieve strong performance in classification tasks, establishing zero-training baselines. In contrast, the performance in regression is poor compared to ML models, likely because regression demands outputs in a large space, and clustering results are similarly limited, which we attribute to the absence of genuine ICL in this setting. Nonetheless, this approach enables low-overhead data analysis and offers a viable alternative to traditional ML pipelines. We further analyze the influence of context size and prompt structure on predictive performance. Our findings suggest that LLMs can serve as general-purpose predictive engines for structured data, with clear strengths in classification and significant limitations in regression and clustering.