Retrieval-Augmented Long-Context Translation for Cultural Image Captioning: Gators submission for AmericasNLP 2026 shared task
Summary
The University of Florida Gators submitted a two-stage system for the AmericasNLP 2026 shared task, focusing on cultural image captioning for Indigenous languages. Their pipeline initially generates Spanish captions from images using a vision-language model. Subsequently, these Spanish captions are translated into target Indigenous languages through retrieval-augmented many-shot prompting, specifically utilizing the Gemini 2.5 Flash model. This system demonstrated strong improvements over the shared task baseline across multiple Indigenous languages. The submission includes a detailed analysis of the roles played by retrieval mechanisms, synthetic exemplars, and morphology-aware prompting in enhancing translation quality. It also discusses critical limitations related to dev-set exemplars, potential cascade errors within the two-stage process, and the effectiveness of chrF++ based evaluation.
Key takeaway
For NLP engineers developing systems for low-resource language translation, consider a cascaded approach. Your team should explore retrieval-augmented many-shot prompting with powerful LLMs like Gemini 2.5 Flash to improve translation quality. Be mindful of potential cascade errors and the limitations of evaluation metrics like chrF++ when designing your pipeline. This method offers a viable path for cultural image captioning.
Key insights
Retrieval-augmented many-shot prompting with a powerful LLM improves Indigenous language translation for image captions.
Principles
- Two-stage pipelines can bridge modality gaps.
- Retrieval augmentation enhances few-shot translation.
- Morphology-aware prompting is beneficial.
Method
A two-stage pipeline: first, a vision-language model generates Spanish captions; then, Gemini 2.5 Flash translates them to target Indigenous languages using retrieval-augmented many-shot prompting.
In practice
- Use a VLM for initial caption generation.
- Employ retrieval for low-resource translation.
- Consider synthetic exemplars for prompting.
Topics
- Retrieval-Augmented Generation
- Image Captioning
- Indigenous Languages
- Machine Translation
- Gemini 2.5 Flash
- AmericasNLP 2026
Best for: Research Scientist, AI Scientist, NLP Engineer
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Editorial summary, takeaway, and curation by AIssential. Original article published by Paper Index on ACL Anthology.