Summary
This paper presents an approach to Sign Language Translation (SLT) that aims to scale the field by addressing limitations in data, model size, and the number of translation directions. The authors' key contributions are:
* Data Scaling: The authors leverage diverse and large-scale datasets, including noisy multilingual YouTube SLT data and augmented SLT data generated from video captions, enabling more robust pretraining.
* Model Scaling: They pretrain SLT models on various sizes, initially fine-tuning them with pretrained (m/By)T5 models, demonstrating the impact of larger models on performance.
* Cross-lingual and Cross-modal Transfer: The authors show that cross-lingual and cross-modal transfer from pretraining on multilingual data improvesSLT performance, even enabling zero-shot translation, translating sign language to a spoken language without explicit training in that direction.
* Open-domain SLT Evaluation: The models are finetuned on five downstream open-domain SLT benchmarks covering five different sign languages, leading to substantial quality improvements over existing state-of-the-art methods.
Strengths
* The paper and approach is well motivated.
* The experiments are generally well thought out.
* The writing quality and analyses are generally good and informative. e.g., Sec 4.2 brought up questions that I had been wondering and did a nice job answering.
* The results relative to SOTA are compelling.
Weaknesses
There are multiple references that claim to be on arXiv but don't seem to exist including the FLEURS-ASL paper. I found at least three instances:
* Garrett Tanzer. Fleurs-asl: Including american sign language in massively multilingual multi- task evaluation. arXiv, 2024.
* Garrett Tanzer. Fingerspelling within sign language translation. arXiv, 2024.
* Garrett Tanzer and Biao Zhang. Youtube-sl-25: A large-scale, open-domain multilingual sign language parallel corpus. arXiv, 2024.
FLEURS-ASL#0 only has 353 sentences but is used for a large percentage of the experiments. I have some question about whether or not these results are likely to generalize, especially given that these sentences were generated by a single person. Given that the FLEURS-ASL paper isn't actually on arXiv (as of July 13) I don't have a way to understand what types of sentences these include. it's important to understand the biases and breadth of what is covered.
Lack of Comparative Analysis: While the paper surpasses the previous state-of-the-art, a more in-depth comparative analysis of other recent SLT methods, including their strengths and weaknesses, would strengthen the paper's argumentation. Yes, Table 4 does show SOTA numbers, but it would be useful to contrast the approaches.
Minor: Phoenix is referred to in Table 4 and 8 descriptions but only acronyms are used in the tables themselves -- it's unclear which acronym is which.
Questions
See questions above. Especially, can you explain the missing references and talk through characterization of the FLEURS-ASL dataset? Can you also confirm that you are not fine-tuning on FLEURS-ASL#0?
Regarding Table 5 and related analysis, is there a reason why BLEURT could have a much higher correlation compared to BLEU or ChrF?
How accurate are the mediapipe landmarks on messy YouTube data? Have you looked at correlations between landmark accuracy and translation quality?
Limitations
Seems reasonable.