Semi-supervised learning loops

Nov 2019

Semi-supervised learning loops are a class of iterative machine-learning workflows that take advantage of the relationships to be found in unlabeled data. These techniques may improve models by combining labeled and unlabeled data sets in various ways. In other cases they compare models trained on different subsets of the data. Unlike either unsupervised learning where a machine infers classes in unlabeled data or supervised techniques where the training set is entirely labeled, semi-supervised techniques take advantage of a small set of labeled data and a much larger set of unlabeled data. Semi-supervised learning is also closely related to active learning techniques where a human is directed to selectively label ambiguous data points. Since expert humans that can accurately label data are a scarce resource and labeling is often the most time-consuming activity in the machine-learning workflow, semi-supervised techniques lower the cost of training and make machine learning feasible for a new class of users.