Summary
In this paper, authors argue that for multimodal LLMs, the previous input formulation is too rigid: either needs to specify the region models should focus on, or brings a verbose object description to refer to the region. A more natural referring expression strategy can help models better understand where the model should pay more attention to and the intent of the input questions. The proposed approach, called Localized Symbolic Knowledge Distillation (LSKD), aims to provide more natural referring expressions. It involves providing literal descriptions of images to a large language model and allowing the model to connect these descriptions with a holistic understanding of the scene. In addition, localized references to specific regions within the image are provided to encourage the model to generate commonsense inferences about those regions. This method effectively distills the large language model's capacity for global and local scene understanding. They demonstrate the effectiveness of this approach by achieving state-of-the-art zero-shot performance on localized visual reasoning benchmarks and conducting human evaluations.
Strengths
Novel research question to distill visual commonsense: Distilling visual commonsense is an interesting question that previous works under-explore. The distilled visual commonsense could provide very useful information for understanding complex situations covered in datasets like VCR, which will make the reasoning more grounded and reliable. Also, this is the first work about automatically acquiring visual commonsense to my best knowledge.
Comprehensive experimental results on downstream tasks: I'm very glad to see the distilled knowledge could further help base models on downstream tasks like VCR, Sherlock and VisualCOMET. Also, the small models can even outperform ChatGPT with the help of LSKD when describing the useful information in localized reasoning process. Besides, authors design experiments to examine the effect of steps in LSKD generation methods, which further make the argument stronger.
Weaknesses
Lack of comparison with Sherlock and VisualCOMET: Although the current experiments support that LSKD is helpful for downstream tasks, I'm still a bit confused if LSKD is better than Sherlock and VisualCOMET knowledge bases. These two datasets are both large-scale and of great quality. It's better to compare with competitive resources, instead of just showing that considering external knowledge will help.
Comparing VL models and ChatGPT is unfair: Although ChatGPT is prompted with verbalizers, it still can only accept text information, which may ignore many visual information in the images. Especially for datasets like VCR, answering questions may need a very careful observation to some detailed places, which is what VL models like BLIP-2 is better at.
Presentation in introduction section is confusing: I don't quite understand the relation between the first and second half of the introduction section. For the first half, I think the authors are trying to say a better referring expression is important. But in the second half (which is the core part of the paper), they just focus on how to distill visual commonsense knowledge. They are a bit connected because both parts mention localized reference, but it has very loose connection with discussion about the quality of referring expression.
Questions
1. Is there any way to apply this method to the datasets with no bounding box annotations? That will further improve the scalability of this method.
2. Is there any study to explore the correlation between the ration of error training instances and the downstream task performance?
3. Could you also apply LSKD to models like CLIP? It seems that in Table 2, they just use BLIP-2 ViT-G to show the effectiveness of LSKD.
4. More qualitative error analysis is welcome in the modified version.
Rating
8: Strong Accept: Technically strong paper, with novel ideas, excellent impact on at least one area, or high-to-excellent impact on multiple areas, with excellent evaluation, resources, and reproducibility, and no unaddressed ethical considerations.
Confidence
4: You are confident in your assessment, but not absolutely certain. It is unlikely, but not impossible, that you did not understand some parts of the submission or that you are unfamiliar with some pieces of related work.
Limitations
The limitations about introducing errors in the intermediate steps are reasonable.