Attribution-based Task-specific Pruning for Multi-task Language Models

Multi-task language models show outstanding performance for various natural language understanding tasks with only a single model. However, these language models inevitably utilize unnecessary large-scale model parameters, even when they are used for only a specific task. In this paper, we propose a novel training-free task-specific pruning method for multi-task language models. Specifically, we utilize an attribution method to compute the importance of each neuron for performing a specific task. Then, we prune task-specifically unimportant neurons using this computed importance. Experimental results on the six widely-used datasets show that our proposed pruning method significantly outperforms baseline compression methods. Also, we extend our method to be applicable in a low-resource setting, where the number of labeled datasets is insufficient.