Category Levels in Hierarchical Text Categorization Stephen D’Alessio author Keitha Murray author Robert Schiaffino author Aaron Kershenbaum author 1998-06 text Proceedings of the Third Conference on Empirical Methods for Natural Language Processing Nancy Ide editor Atro Voutilainen editor Association for Computational Linguistics Palacio de Exposiciones y Congresos, Granada, Spain conference publication dalessio-etal-1998-category https://aclanthology.org/W98-1508/ 1998-06 61 70