论文标题
结合多任务学习中的模块化技能
Combining Modular Skills in Multitask Learning
论文作者
论文摘要
模块化设计鼓励神经模型解开和重组不同的知识方面,以更加系统地将其推广到新任务。在这项工作中,我们假设每个任务都与(潜在的)库存中的潜在离散技能子集相关联。反过来,技能对应于参数效率(稀疏 /低级别)模型参数。通过共同学习这些和任务技能分配矩阵,每个任务的网络都可以作为主动技能参数的平均值进行实例化。为了偏爱跨任务的非平凡软分区,我们尝试了一系列的归纳偏见,例如先验和两速学习率。我们在两个主要环境上评估了潜在技能模型:1)在8个级别的Babyai平台上进行接地教学的多任务加固学习; 2)在CrossFit上预先训练的文本到文本生成模型的几乎没有改编,这是一个包括160个NLP任务的基准。我们发现,与具有完全共享,特定于任务或有条件生成的参数的基线相比,网络的模块化设计显着提高了强化学习中的样本效率,而监督学习中的样本效率很少,而在跨任务中纠缠了知识。此外,我们还展示了离散技能如何帮助解释性,因为它们会产生明确的任务层次结构。
A modular design encourages neural models to disentangle and recombine different facets of knowledge to generalise more systematically to new tasks. In this work, we assume that each task is associated with a subset of latent discrete skills from a (potentially small) inventory. In turn, skills correspond to parameter-efficient (sparse / low-rank) model parameterisations. By jointly learning these and a task-skill allocation matrix, the network for each task is instantiated as the average of the parameters of active skills. To favour non-trivial soft partitions of skills across tasks, we experiment with a series of inductive biases, such as an Indian Buffet Process prior and a two-speed learning rate. We evaluate our latent-skill model on two main settings: 1) multitask reinforcement learning for grounded instruction following on 8 levels of the BabyAI platform; and 2) few-shot adaptation of pre-trained text-to-text generative models on CrossFit, a benchmark comprising 160 NLP tasks. We find that the modular design of a network significantly increases sample efficiency in reinforcement learning and few-shot generalisation in supervised learning, compared to baselines with fully shared, task-specific, or conditionally generated parameters where knowledge is entangled across tasks. In addition, we show how discrete skills help interpretability, as they yield an explicit hierarchy of tasks.