CGM: Copy Mechanism GPT with Mask for Ellipsis and Anaphora Resolution in Dialogue

GPT (Generative Pre-trained Transformer) is a generative language model that demonstrates outstanding performance in the field of text generation. Generally, the attention mechanism of the transformer model behaves similarly to a copy distribution. However, due to the absence of a dedicated encoder, it is challenging to ensure that the input is retained for generation. We propose a model that emphasizes the copy mechanism in GPT. We generate masks for the input words to initialize the distribution and explicitly encourage copying through training. To demonstrate the effectiveness of our approach, we conducted experiments to restore ellipsis and anaphora in dialogue. In a single domain, we achieved 0.4319 (BLEU), 0.6408 (Rouge-L), 0.9040 (simCSE), and 0.9070 (BERTScore), while in multi-domain settings we obtained 0.4611 (BLEU), 0.6379 (Rouge-L), 0.8902 (simCSE), and 0.8999 (BERTScore). Additionally, we evaluated the operation of the copy mechanism on out-of-domain data, yielding excellent results. We anticipate that applying the copy mechanism to GPT will be useful for utilizing language models in constrained situations.