Long-Form Answers to Visual Questions from Blind and Low Vision People

Abstract

Vision language models can now generate long-form answers to questions about images – long-form visual question answers (LFVQA). We contribute VizWiz-LF, a dataset of long-form answers to visual questions posed by blind and low vision (BLV) users. VizWiz-LF contains 4.2k long-form answers to 600 visual questions, collected from human expert describers and six VQA models. We develop and annotate functional roles of sentences of LFVQA and demonstrate that long-form answers contain information beyond the question answer such as explanations and suggestions to retake photos. We further conduct automatic and human evaluations involving BLV and sighted people to evaluate long-form answers. While BLV people perceive both human-written and generated long-form answers as plausible, generated answers often hallucinate incorrect visual details, especially for unanswerable visual questions (e.g., blurry or irrelevant images). To reduce hallucinations, we evaluate VQA models on their ability to abstain from answering unanswerable questions.