Lexpansion: Evaluating Dictionary Based Lexicon Expansion for Social Media Analysis

Researchers Mohamed Bahgat, Steven R Wilson, and Walid Magdy introduced Lexpansion, a supervised learning approach that uses dictionary definitions as input features to a BERT transformer model to expand lexicons for social media analysis. In their study presented at the First Workshop on Integrating NLP and Psychology to Study Social Interactions (NLPSI) @ICWSM '25 in Copenhagen, Denmark, they found dictionary-based expansion to be robust across varying dictionary properties, and they released the expanded lexicons, code, and pretrained models.

Abstract Lexicons are indispensable tools for textual analysis through labelled term associations.Despite their utility, lexicons are static and require manual effort to curate and maintain.Regular updates are essential to stay relevant amid semantic shifts and neologisms during language evolution.In this work, we explore the potential of supervised learning for expanding lexicons using dictionaries.We study the effect of using dictionaries with varying properties such as noise, size, labels, structure and curation method.Definitions are used as input features to a transformer model BERT that assigns categories to terms.We analyse the expansions using varying English dictionaries and lexicons for estimated accuracy, coverage and labelling consistency and apply the expanded versions to a downstream task.Our analyses show dictionary based expansion is a robust approach.We release our expanded lexicons, code, and pretrained models.- Anthology ID: - 2025.nlpsi-1.2 - Volume: Proceedings of the First Workshop on Integrating NLP and Psychology to Study Social Interactions NLPSI @ICWSM ’25 /volumes/2025.nlpsi-1/ - Month: - June - Year: - 2025 - Address: - Copenhagen, Denmark - Editors: Aswathy Velutharambath /people/aswathy-velutharambath/unverified/ , Sofie Labat /people/sofie-labat/ , Neele Falk /people/neele-falk/ , Flor Miriam Plaza-del-Arco /people/flor-miriam-plaza-del-arco/ , Roman Klinger /people/roman-klinger/ , Véronique Hoste /people/veronique-hoste/unverified/ - Venues: NLPSI /venues/nlpsi/ | WS /venues/ws/ - SIG: - Publisher: - Association for the Advancement of Artificial Intelligence www.aaai.org - Note: - Pages: - 11–27 - Language: - URL: https://aclanthology.org/2025.nlpsi-1.2/ https://aclanthology.org/2025.nlpsi-1.2/ - DOI: 10.36190/2025.33 https://doi.org/10.36190/2025.33 - Cite ACL : - Mohamed Bahgat, Steven R Wilson, and Walid Magdy. 2025. Lexpansion: Evaluating Dictionary Based Lexicon Expansion for Social Media Analysis https://aclanthology.org/2025.nlpsi-1.2/ . In Proceedings of the First Workshop on Integrating NLP and Psychology to Study Social Interactions NLPSI @ICWSM ’25 , pages 11–27, Copenhagen, Denmark. Association for the Advancement of Artificial Intelligence www.aaai.org . - Cite Informal : Lexpansion: Evaluating Dictionary Based Lexicon Expansion for Social Media Analysis https://aclanthology.org/2025.nlpsi-1.2/ Bahgat et al., NLPSI 2025 - PDF: https://aclanthology.org/2025.nlpsi-1.2.pdf https://aclanthology.org/2025.nlpsi-1.2.pdf