Zhengping Zhou


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Beyond Positive Scaling: How Negation Impacts Scaling Trends of Language Models
Yuhui Zhang | Michihiro Yasunaga | Zhengping Zhou | Jeff Z. HaoChen | James Zou | Percy Liang | Serena Yeung
Findings of the Association for Computational Linguistics: ACL 2023

Language models have been shown to exhibit positive scaling, where performance improves as models are scaled up in terms of size, compute, or data. In this work, we introduce NeQA, a dataset consisting of questions with negation in which language models do not exhibit straightforward positive scaling. We show that this task can exhibit inverse scaling, U-shaped scaling, or positive scaling, and the three scaling trends shift in this order as we use more powerful prompting methods or model families. We hypothesize that solving NeQA depends on two subtasks: question answering (task 1) and negation understanding (task 2). We find that task 1 has linear scaling, while task 2 has sigmoid-shaped scaling with an emergent transition point, and composing these two scaling trends yields the final scaling trend of NeQA. Our work reveals and provides a way to analyze the complex scaling trends of language models.


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Enhancing Transformer with Sememe Knowledge
Yuhui Zhang | Chenghao Yang | Zhengping Zhou | Zhiyuan Liu
Proceedings of the 5th Workshop on Representation Learning for NLP

While large-scale pretraining has achieved great success in many NLP tasks, it has not been fully studied whether external linguistic knowledge can improve data-driven models. In this work, we introduce sememe knowledge into Transformer and propose three sememe-enhanced Transformer models. Sememes, by linguistic definition, are the minimum semantic units of language, which can well represent implicit semantic meanings behind words. Our experiments demonstrate that introducing sememe knowledge into Transformer can consistently improve language modeling and downstream tasks. The adversarial test further demonstrates that sememe knowledge can substantially improve model robustness.