An Analysis of Visual Question Answering Algorithms
This addresses evaluation flaws in VQA for researchers, but it is incremental as it focuses on dataset and analysis improvements rather than a new method.
The paper tackles the problem of inflated and biased evaluation in visual question answering (VQA) by analyzing existing algorithms using a new dataset with over 1.6 million questions and introducing meaningless questions to force reasoning, resulting in new evaluation schemes that reveal how simple models can outperform complex ones by exploiting easy question categories.
In visual question answering (VQA), an algorithm must answer text-based questions about images. While multiple datasets for VQA have been created since late 2014, they all have flaws in both their content and the way algorithms are evaluated on them. As a result, evaluation scores are inflated and predominantly determined by answering easier questions, making it difficult to compare different methods. In this paper, we analyze existing VQA algorithms using a new dataset. It contains over 1.6 million questions organized into 12 different categories. We also introduce questions that are meaningless for a given image to force a VQA system to reason about image content. We propose new evaluation schemes that compensate for over-represented question-types and make it easier to study the strengths and weaknesses of algorithms. We analyze the performance of both baseline and state-of-the-art VQA models, including multi-modal compact bilinear pooling (MCB), neural module networks, and recurrent answering units. Our experiments establish how attention helps certain categories more than others, determine which models work better than others, and explain how simple models (e.g. MLP) can surpass more complex models (MCB) by simply learning to answer large, easy question categories.