论文标题
理解对比度学习需要纳入归纳偏见
Understanding Contrastive Learning Requires Incorporating Inductive Biases
论文作者
论文摘要
对比学习是一种自我监督学习的流行形式,它鼓励相同输入的增强(视图)与不同输入的增强相比具有更多相似的表示。从理论上讲,最新的尝试解释了下游分类任务的对比度学习的成功,这是根据{\ em abmentations}的属性以及表示表示的{\ em对比度损失}的价值来保证的。我们证明,这种分析忽略了功能类别和训练算法的{\ em感应偏见},无法充分解释对比度学习的成功,甚至在某些情况下也可以空虚。关于图像和文本领域的广泛实验突出了此问题的普遍性 - 尽管具有相同的增强和对比损失,但在下游任务上的不同功能类和算法的行为却大不相同。对线性表示类别进行了理论分析,其中融合了功能类别的电感偏差,与先前的分析相比,对比度学习可以在较严格的条件下工作。
Contrastive learning is a popular form of self-supervised learning that encourages augmentations (views) of the same input to have more similar representations compared to augmentations of different inputs. Recent attempts to theoretically explain the success of contrastive learning on downstream classification tasks prove guarantees depending on properties of {\em augmentations} and the value of {\em contrastive loss} of representations. We demonstrate that such analyses, that ignore {\em inductive biases} of the function class and training algorithm, cannot adequately explain the success of contrastive learning, even {\em provably} leading to vacuous guarantees in some settings. Extensive experiments on image and text domains highlight the ubiquity of this problem -- different function classes and algorithms behave very differently on downstream tasks, despite having the same augmentations and contrastive losses. Theoretical analysis is presented for the class of linear representations, where incorporating inductive biases of the function class allows contrastive learning to work with less stringent conditions compared to prior analyses.