Recent large language models (LLM) exhibit sub-optimal performance on low-resource languages, as the training data of these models is usually dominated by English and other high-resource languages. Furthermore, it is challenging to train models for low-resource languages, especially from scratch, due to a lack of high quality training data. Adapting pretrained LLMs reduces the need for data in the new language while also providing cross lingual transfer capabilities. However, naively adapting to new languages leads to catastrophic forgetting and poor tokenizer efficiency. In this work, we study how to efficiently adapt any existing pretrained LLM to a new language without running into these issues. In particular, we improve the encoding efficiency of the tokenizer by adding new tokens from the target language and study the data mixing recipe to mitigate forgetting. Our experiments on adapting an English LLM to Hungarian and Thai show that our recipe can reach better performance than open source models on the target language, with minimal regressions on English.

本文研究如何有效地将任何现有的预训练大型语言模型适应到新的语言中，避免灾难性遗忘和标记器效率低下的问题，并通过添加目标语言的新标记和研究数据混合配方提高标记器的编码效率。实验证明，我们的配方在将英语预训练大型语言模型适应到匈牙利语和泰语方面，能够达到比开源模型更好的性能，同时对英语的回归影响很小。

高效地将预先训练好的语言模型适应新语言