Skip to main content
Academic

Beyond Subtokens: A Rich Character Embedding for Low-resource and Morphologically Complex Languages

arXiv:2602.21377v1 Announce Type: new Abstract: Tokenization and sub-tokenization based models like word2vec, BERT and the GPTs are the state-of-the-art in natural language processing. Typically, these approaches have limitations with respect to their input representation. They fail to fully capture orthographic similarities and morphological variations, especially in highly inflected and under-resource languages. To mitigate this problem, we propose to computes word vectors directly from character strings, integrating both semantic and syntactic information. We denote this transformer-based approach Rich Character Embeddings (RCE). Furthermore, we propose a hybrid model that combines transformer and convolutional mechanisms. Both vector representations can be used as a drop-in replacement for dictionary- and subtoken-based word embeddings in existing model architectures. It has the potential to improve performance for both large context-based language models like BERT and small model

F
Felix Schneider, Maria Gogolev, Sven Sickert, Joachim Denzler
· · 1 min read · 4 views

arXiv:2602.21377v1 Announce Type: new Abstract: Tokenization and sub-tokenization based models like word2vec, BERT and the GPTs are the state-of-the-art in natural language processing. Typically, these approaches have limitations with respect to their input representation. They fail to fully capture orthographic similarities and morphological variations, especially in highly inflected and under-resource languages. To mitigate this problem, we propose to computes word vectors directly from character strings, integrating both semantic and syntactic information. We denote this transformer-based approach Rich Character Embeddings (RCE). Furthermore, we propose a hybrid model that combines transformer and convolutional mechanisms. Both vector representations can be used as a drop-in replacement for dictionary- and subtoken-based word embeddings in existing model architectures. It has the potential to improve performance for both large context-based language models like BERT and small models like word2vec for under-resourced and morphologically rich languages. We evaluate our approach on various tasks like the SWAG, declension prediction for inflected languages, metaphor and chiasmus detection for various languages. Our experiments show that it outperforms traditional token-based approaches on limited data using OddOneOut and TopK metrics.

Executive Summary

This article proposes a novel approach to natural language processing, introducing Rich Character Embeddings (RCE) that directly compute word vectors from character strings, capturing both semantic and syntactic information. The proposed hybrid model combines transformer and convolutional mechanisms, outperforming traditional token-based approaches on limited data. The approach shows promise for under-resourced and morphologically rich languages, with potential applications in various tasks such as declension prediction, metaphor detection, and language modeling.

Key Points

  • Introduction of Rich Character Embeddings (RCE) for natural language processing
  • Proposal of a hybrid model combining transformer and convolutional mechanisms
  • Evaluation of the approach on various tasks and languages, including SWAG, declension prediction, and metaphor detection

Merits

Improved Performance on Limited Data

The proposed approach outperforms traditional token-based approaches on limited data, making it suitable for under-resourced languages.

Capture of Morphological Variations

RCE captures orthographic similarities and morphological variations, especially in highly inflected languages.

Demerits

Computational Complexity

The proposed hybrid model may increase computational complexity, potentially affecting training and inference times.

Limited Evaluation

The approach is evaluated on a limited set of tasks and languages, requiring further experimentation to confirm its effectiveness.

Expert Commentary

The proposed Rich Character Embeddings approach represents a significant advancement in natural language processing, particularly for under-resourced and morphologically rich languages. By capturing both semantic and syntactic information, RCE has the potential to improve performance on a range of tasks, from language modeling to text classification. However, further research is needed to fully explore the capabilities and limitations of this approach, including its computational complexity and evaluation on a broader set of languages and tasks.

Recommendations

  • Further evaluation of the proposed approach on a wider range of languages and tasks
  • Investigation of the computational complexity and potential optimizations for the hybrid model

Sources