TinyBERT: Distilling BERT for Natural Language Understanding Xiaoqi Jiao1∗,y Yichun Yin2∗z, Lifeng Shang2z, Xin Jiang2 Xiao Chen2, Linlin Li3, Fang Wang1z and Qun Liu2 1Key Laboratory of Information Storage System, Huazhong University of Science and Technology, Wuhan National Laboratory for Optoelectronics 2Huawei Noah’s Ark Lab 3Huawei Technologies Co., Ltd. fjiaoxiaoqi,
[email protected] fyinyichun,shang.lifeng,
[email protected] fchen.xiao2,lynn.lilinlin,
[email protected] Abstract natural language processing (NLP). Pre-trained lan- guage models (PLMs), such as BERT (Devlin et al., Language model pre-training, such as BERT, has significantly improved the performances 2019), XLNet (Yang et al., 2019), RoBERTa (Liu of many natural language processing tasks. et al., 2019), ALBERT (Lan et al., 2020), T5 (Raf- However, pre-trained language models are usu- fel et al., 2019) and ELECTRA (Clark et al., 2020), ally computationally expensive, so it is diffi- have achieved great success in many NLP tasks cult to efficiently execute them on resource- (e.g., the GLUE benchmark (Wang et al., 2018) restricted devices. To accelerate inference and the challenging multi-hop reasoning task (Ding and reduce model size while maintaining et al., 2019)). However, PLMs usually have a accuracy, we first propose a novel Trans- former distillation method that is specially de- large number of parameters and take long infer- signed for knowledge distillation (KD) of the ence time, which are difficult to be deployed on Transformer-based models. By leveraging this edge devices such as mobile phones. Recent stud- new KD method, the plenty of knowledge en- ies (Kovaleva et al., 2019; Michel et al., 2019; Voita coded in a large “teacher” BERT can be ef- et al., 2019) demonstrate that there is redundancy fectively transferred to a small “student” Tiny- in PLMs.