Re-Ranking Words to Improve Interpretability of Automatically Generated Topics

Areej Alokaili, Nikolaos Aletras, Mark Stevenson


Abstract
Topics models, such as LDA, are widely used in Natural Language Processing. Making their output interpretable is an important area of research with applications to areas such as the enhancement of exploratory search interfaces and the development of interpretable machine learning models. Conventionally, topics are represented by their n most probable words, however, these representations are often difficult for humans to interpret. This paper explores the re-ranking of topic words to generate more interpretable topic representations. A range of approaches are compared and evaluated in two experiments. The first uses crowdworkers to associate topics represented by different word rankings with related documents. The second experiment is an automatic approach based on a document retrieval task applied on multiple domains. Results in both experiments demonstrate that re-ranking words improves topic interpretability and that the most effective re-ranking schemes were those which combine information about the importance of words both within topics and their relative frequency in the entire corpus. In addition, close correlation between the results of the two evaluation approaches suggests that the automatic method proposed here could be used to evaluate re-ranking methods without the need for human judgements.
Anthology ID:
W19-0404
Volume:
Proceedings of the 13th International Conference on Computational Semantics - Long Papers
Month:
May
Year:
2019
Address:
Gothenburg, Sweden
Editors:
Simon Dobnik, Stergios Chatzikyriakidis, Vera Demberg
Venue:
IWCS
SIG:
SIGSEM
Publisher:
Association for Computational Linguistics
Note:
Pages:
43–54
Language:
URL:
https://aclanthology.org/W19-0404
DOI:
10.18653/v1/W19-0404
Bibkey:
Cite (ACL):
Areej Alokaili, Nikolaos Aletras, and Mark Stevenson. 2019. Re-Ranking Words to Improve Interpretability of Automatically Generated Topics. In Proceedings of the 13th International Conference on Computational Semantics - Long Papers, pages 43–54, Gothenburg, Sweden. Association for Computational Linguistics.
Cite (Informal):
Re-Ranking Words to Improve Interpretability of Automatically Generated Topics (Alokaili et al., IWCS 2019)
Copy Citation:
PDF:
https://preview.aclanthology.org/landing_page/W19-0404.pdf
Code
 areejokaili/topic_reranking