Extracting Lexical Features from Dialects via Interpretable Dialect Classifiers
Roy Xie, Orevaoghene Ahia, Yulia Tsvetkov, Antonios Anastasopoulos
TL;DR
The paper tackles the challenge of identifying dialect-specific lexical features without relying on expert linguists by leveraging interpretable dialect classifiers. It combines post-hoc (Leave-One-Out) and intrinsic (SelfExplain) explanation methods to extract local explanations and maps them to global lexical features through a corpus-level TF-IDF workflow. Experiments on Mandarin CN-TW, Italian dialects (including Sicilian), and Low Saxon demonstrate high explanation sufficiency, favorable plausibility, and strong lexical-feature extraction performance, with automatic and human validations supporting the approach. This work provides a framework for explainable dialectology, enabling researchers to uncover language-unique vocabulary and offering practical insights for NLP applications involving dialectal variation.
Abstract
Identifying linguistic differences between dialects of a language often requires expert knowledge and meticulous human analysis. This is largely due to the complexity and nuance involved in studying various dialects. We present a novel approach to extract distinguishing lexical features of dialects by utilizing interpretable dialect classifiers, even in the absence of human experts. We explore both post-hoc and intrinsic approaches to interpretability, conduct experiments on Mandarin, Italian, and Low Saxon, and experimentally demonstrate that our method successfully identifies key language-specific lexical features that contribute to dialectal variations.
