Annotation-Free Class-Incremental Learning

Despite significant progress in continual learning ranging from architectural novelty to clever strategies for mitigating catastrophic forgetting; most existing methods rest on a strong but unrealistic assumption: "the availability of labeled data throughout the learning process". In real-world scenarios, however, data often arrives sequentially and without annotations, rendering conventional approaches impractical. In this work, we revisit the fundamental assumptions of continual learning and ask: Can current systems adapt when labels are absent and tasks emerge incrementally over time? T o this end, we introduce Annotation-Free Class-Incremental Learning (AF-CIL), a more realistic and challenging paradigm where unlabeled data arrives continuously, and the learner must incrementally acquire new classes without any supervision. T o enable effective learning under AF-CIL, we propose CrossW orld-CL, a Cross Domain W orld Guided Continual Learning framework that incorporates external world knowledge as a stable auxiliary source. The method retrieves semantically related ImageNet classes for each downstream category, maps downstream and ImageNet features through a cross-domain alignment strategy and finally introduce a novel replay strategy. This design lets the model uncover semantic structure without annotations while keeping earlier knowledge intact.