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Poster
COCO-LM: Correcting and Contrasting Text Sequences for Language Model Pretraining
Yu Meng · Chenyan Xiong · Payal Bajaj · saurabh tiwary · Paul Bennett · Jiawei Han · XIA SONG

Tue Dec 07 08:30 AM -- 10:00 AM (PST) @
in Poster Session 1 »

We present a self-supervised learning framework, COCO-LM, that pretrains Language Models by COrrecting and COntrasting corrupted text sequences. Following ELECTRA-style pretraining, COCO-LM employs an auxiliary language model to corrupt text sequences, upon which it constructs two new tasks for pretraining the main model. The first token-level task, Corrective Language Modeling, is to detect and correct tokens replaced by the auxiliary model, in order to better capture token-level semantics. The second sequence-level task, Sequence Contrastive Learning, is to align text sequences originated from the same source input while ensuring uniformity in the representation space. Experiments on GLUE and SQuAD demonstrate that COCO-LM not only outperforms recent state-of-the-art pretrained models in accuracy, but also improves pretraining efficiency. It achieves the MNLI accuracy of ELECTRA with 50% of its pretraining GPU hours. With the same pretraining steps of standard base/large-sized models, COCO-LM outperforms the previous best models by 1+ GLUE average points.

Keywords: Self-Supervised Learning · Contrastive Learning

Author Information

Yu Meng (University of Illinois at Urbana-Champaign)
Chenyan Xiong (Microsoft Research AI)
Payal Bajaj (Microsoft)
saurabh tiwary (Microsoft)
Paul Bennett (Microsoft Research)
Jiawei Han (University of Illinois at Urbana-Champaign)
XIA SONG (Microsoft)

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