Scale Can't Overcome Pragmatics: The Impact of Reporting Bias on Vision-Language Reasoning
This study addresses the limited reasoning capabilities of current vision-language models (VLMs), which stem from reporting bias in training data that systematically omits implicit information—such as spatial relations, temporal dynamics, negation, and counting. For the first time, the authors formally integrate pragmatic theories of reporting bias into vision-language learning, constructing a targeted evaluation benchmark to assess multiple models, including OpenCLIP, LLaVA-1.5, and Molmo. Their findings reveal that merely scaling up data volume or incorporating multilingual corpora fails to rectify these reasoning gaps. In contrast, explicitly designing and integrating annotations that surface such implicit information substantially enhances model performance. This work challenges the prevailing “scale-is-all-you-need” paradigm, underscoring the necessity of deliberately curating training data that supports robust multimodal reasoning.