Meta-Query-Net: Resolving Purity-Informativeness Dilemma in Open-set Active Learning
This addresses the challenge of selecting informative samples while filtering noise in active learning, which is incremental as it builds on prior work to optimize the trade-off.
The paper tackles the purity-informativeness dilemma in open-set active learning by proposing Meta-Query-Net (MQ-Net), which adaptively balances these factors and achieves a 20.14% accuracy improvement over state-of-the-art methods.
Unlabeled data examples awaiting annotations contain open-set noise inevitably. A few active learning studies have attempted to deal with this open-set noise for sample selection by filtering out the noisy examples. However, because focusing on the purity of examples in a query set leads to overlooking the informativeness of the examples, the best balancing of purity and informativeness remains an important question. In this paper, to solve this purity-informativeness dilemma in open-set active learning, we propose a novel Meta-Query-Net,(MQ-Net) that adaptively finds the best balancing between the two factors. Specifically, by leveraging the multi-round property of active learning, we train MQ-Net using a query set without an additional validation set. Furthermore, a clear dominance relationship between unlabeled examples is effectively captured by MQ-Net through a novel skyline regularization. Extensive experiments on multiple open-set active learning scenarios demonstrate that the proposed MQ-Net achieves 20.14% improvement in terms of accuracy, compared with the state-of-the-art methods.