Analyzing analytical methods: The case of phonology in neural models of spoken language

Grzegorz Chrupała, Bertrand Higy, Afra Alishahi


Abstract
Given the fast development of analysis techniques for NLP and speech processing systems, few systematic studies have been conducted to compare the strengths and weaknesses of each method. As a step in this direction we study the case of representations of phonology in neural network models of spoken language. We use two commonly applied analytical techniques, diagnostic classifiers and representational similarity analysis, to quantify to what extent neural activation patterns encode phonemes and phoneme sequences. We manipulate two factors that can affect the outcome of analysis. First, we investigate the role of learning by comparing neural activations extracted from trained versus randomly-initialized models. Second, we examine the temporal scope of the activations by probing both local activations corresponding to a few milliseconds of the speech signal, and global activations pooled over the whole utterance. We conclude that reporting analysis results with randomly initialized models is crucial, and that global-scope methods tend to yield more consistent and interpretable results and we recommend their use as a complement to local-scope diagnostic methods.
Anthology ID:
2020.acl-main.381
Volume:
Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics
Month:
July
Year:
2020
Address:
Online
Editors:
Dan Jurafsky, Joyce Chai, Natalie Schluter, Joel Tetreault
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
4146–4156
Language:
URL:
https://aclanthology.org/2020.acl-main.381
DOI:
10.18653/v1/2020.acl-main.381
Bibkey:
Cite (ACL):
Grzegorz Chrupała, Bertrand Higy, and Afra Alishahi. 2020. Analyzing analytical methods: The case of phonology in neural models of spoken language. In Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics, pages 4146–4156, Online. Association for Computational Linguistics.
Cite (Informal):
Analyzing analytical methods: The case of phonology in neural models of spoken language (Chrupała et al., ACL 2020)
Copy Citation:
PDF:
https://aclanthology.org/2020.acl-main.381.pdf
Video:
 http://slideslive.com/38928815
Code
 gchrupala/analyzing-analytical-methods