Human vs LLM-Generated Alt Text for STEM Image Accessibility: A Comparative Study
Marco Cardia, Letizia Angileri, Camilla Poggianti, Barbara Leporini · 2026
Image descriptions are a fundamental aspect of web accessibility, allowing blind and low-vision users to access visual information through assistive technologies such as screen readers. Despite their importance, high-quality alternative text is often missing or inadequate, especially for complex images like diagrams, graphs, and other STEM-related content. Recent advances in generative artificial intelligence and large language models (LLMs) have renewed interest in automatically generating image descriptions, raising the question of whether these systems can reliably support accessibility at scale.