Abstract
Subword-level information is crucial for capturing the meaning and morphology of words, especially for out-of-vocabulary entries. We propose CNN- and RNN-based subword-level composition functions for learning word embeddings, and systematically compare them with popular word-level and subword-level models (Skip-Gram and FastText). Additionally, we propose a hybrid training scheme in which a pure subword-level model is trained jointly with a conventional word-level embedding model based on lookup-tables. This increases the fitness of all types of subword-level word embeddings; the word-level embeddings can be discarded after training, leaving only compact subword-level representation with much smaller data volume. We evaluate these embeddings on a set of intrinsic and extrinsic tasks, showing that subword-level models have advantage on tasks related to morphology and datasets with high OOV rate, and can be combined with other types of embeddings.- Anthology ID:
 - W18-1205
 - Volume:
 - Proceedings of the Second Workshop on Subword/Character LEvel Models
 - Month:
 - June
 - Year:
 - 2018
 - Address:
 - New Orleans
 - Editors:
 - Manaal Faruqui, Hinrich Schütze, Isabel Trancoso, Yulia Tsvetkov, Yadollah Yaghoobzadeh
 - Venue:
 - SCLeM
 - SIG:
 - Publisher:
 - Association for Computational Linguistics
 - Note:
 - Pages:
 - 38–48
 - Language:
 - URL:
 - https://aclanthology.org/W18-1205
 - DOI:
 - 10.18653/v1/W18-1205
 - Cite (ACL):
 - Bofang Li, Aleksandr Drozd, Tao Liu, and Xiaoyong Du. 2018. Subword-level Composition Functions for Learning Word Embeddings. In Proceedings of the Second Workshop on Subword/Character LEvel Models, pages 38–48, New Orleans. Association for Computational Linguistics.
 - Cite (Informal):
 - Subword-level Composition Functions for Learning Word Embeddings (Li et al., SCLeM 2018)
 - PDF:
 - https://preview.aclanthology.org/ingest-acl-2023-videos/W18-1205.pdf
 - Data
 - IMDb Movie Reviews