Cross-View LLMing: Towards Unified Cross-Lingual Cross-Modal Pre-training
The paper "Cross-View LLMing: Towards Unified Cross-Lingual Cross-Modal Pre-training" introduces a novel pre-training framework named Cross-View LLMing (CVLM). The primary goal of this framework is to unify the methodologies employed in cross-lingual and cross-modal pre-training. Cross-lingual pre-training typically focuses on alignments across different languages, while cross-modal pre-training aligns representations across different data modalities, such as text and images. This paper posits that both tasks fundamentally aim to align disparate data views within a shared semantic space.
Methodology
The core innovation of this paper is treating multi-modal data (image-caption pairs) and multi-lingual data (parallel sentence pairs) as different views of the same semantic object. The CVLM framework leverages Transformer-based architectures, applying conditional masked LLMing and contrastive learning to maximize mutual information between paired data views. Specifically, the authors suggest that both multi-modal and multi-lingual datasets can be used interchangeably as input to CVLM, with representations fused through a shared cross-attention mechanism.
Model and Pre-training Strategy
The framework is instantiated in the Cross-lingual Cross-modal LLM (CCLM), which combines pre-trained image and text encoders alongside a fusion model for integrated representation. CCLM is evaluated across multiple tasks, benefiting from the mutual information maximization achieved through the multi-type input data. The CCLM's architecture's modularity allows it to seamlessly transition between tasks utilizing image-caption or sentence pairs without altering the underlying process.
Experimental Results
CCLM was empirically validated on the IGLUE benchmark, which encompasses diverse vision-language understanding and retrieval tasks across multiple languages. Remarkably, CCLM demonstrated an average improvement exceeding 10% over the state-of-the-art models in multi-modal tasks. Furthermore, it achieved superior zero-shot cross-lingual transfer performance over English-only models, validating the utility of the unified pre-training approach.
Moreover, the ablation studies conducted substantiate the necessity of shared architectures and objectives for effective cross-lingual and cross-modal transfer. The inclusion of parallel text data, notably neglected by previous models, proved pivotal in enhancing representations within the common semantic space.
Practical and Theoretical Implications
From a practical perspective, the CVLM framework, particularly in its CCLM embodiment, proffers significant advancements in multi-lingual, multi-modal pre-trained model applicability. By diminishing the performance gap in non-English tasks, CCLM enables wider real-world application scopes for multi-modal tasks. Theoretically, CVLM underscores the viability of generalized pre-training strategies wherein cross-lingual and cross-modal tasks are unified beyond traditional separations. This seeks inspiration and potential enhancements from the synergies established between these traditionally distinct areas.
Future Directions
The research sets a compelling precedent for future explorations into integrating additional modalities, such as audio and video, within the CVLM framework. Expanding CVLM to embrace broader modalities could further generalize pre-training applications and potentially inspire new approaches and methodologies in AI model pre-training.
In conclusion, this paper constitutes a significant advancement in the integration of cross-lingual and cross-modal learning, reflecting promising avenues for both theoretical research and practical applications in AI.