Semi-Supervised Learning with Competitive Infection Models
This work addresses the challenge of effectively combining labeled and unlabeled data in semi-supervised learning, offering an incremental improvement over existing graph-based methods.
The paper tackled the problem of label propagation in semi-supervised learning by proposing a method based on dynamic infection processes, achieving competitive performance across multiple benchmarks.
The goal in semi-supervised learning is to effectively combine labeled and unlabeled data. One way to do this is by encouraging smoothness across edges in a graph whose nodes correspond to input examples. In many graph-based methods, labels can be thought of as propagating over the graph, where the underlying propagation mechanism is based on random walks or on averaging dynamics. While theoretically elegant, these dynamics suffer from several drawbacks which can hurt predictive performance. Our goal in this work is to explore alternative mechanisms for propagating labels. In particular, we propose a method based on dynamic infection processes, where unlabeled nodes can be "infected" with the label of their already infected neighbors. Our algorithm is efficient and scalable, and an analysis of the underlying optimization objective reveals a surprising relation to other Laplacian approaches. We conclude with a thorough set of experiments across multiple benchmarks and various learning settings.