What is active learning?

Active learning is a special case of machine learning in which a learning algorithm can interactively query a user (or other information source) to label new data points with the desired outputs. This approach is particularly useful when labeled data is scarce or expensive to obtain, as the algorithm can strategically select the most informative data points to label, thereby maximizing performance with minimal labeling effort. It is commonly used in scenarios such as image classification, text classification, and bioinformatics, where obtaining labels requires significant human effort or expert knowledge.