Multi-label active learning based on submodular functions.

In the data collection task, it is more expensive to annotate the instance in multi-label learning problem, since each instance is associated with multiple labels. Therefore it is more important to adopt active learning method in multi-label learning to reduce the labeling cost. Recent researches indicate submodular function optimization works well on subset selection problem and provides theoretical performance guarantees while simultaneously retaining extremely fast optimization. In this paper, we propose a query strategy by constructing a submodular function for the selected instance-label pairs, which can measure and combine the informativeness and representativeness. Thus the active learning problem can be formulated as a submodular function maximization problem, which can be solved efficiently and effectively by a simple greedy lazy algorithm. Experimental results show that the proposed approach outperforms several state-of-the-art multi-label active learning methods.