Explaining Text Classifiers with Counterfactual Representations

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Lemberger, Pirmin, Saillenfest, Antoine
Formato: Preprint
Publicado: 2024
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866914947300065280
author Lemberger, Pirmin
Saillenfest, Antoine
author_facet Lemberger, Pirmin
Saillenfest, Antoine
contents One well motivated explanation method for classifiers leverages counterfactuals which are hypothetical events identical to real observations in all aspects except for one feature. Constructing such counterfactual poses specific challenges for texts, however, as some attribute values may not necessarily align with plausible real-world events. In this paper we propose a simple method for generating counterfactuals by intervening in the space of text representations which bypasses this limitation. We argue that our interventions are minimally disruptive and that they are theoretically sound as they align with counterfactuals as defined in Pearl's causal inference framework. To validate our method, we conducted experiments first on a synthetic dataset and then on a realistic dataset of counterfactuals. This allows for a direct comparison between classifier predictions based on ground truth counterfactuals - obtained through explicit text interventions - and our counterfactuals, derived through interventions in the representation space. Eventually, we study a real world scenario where our counterfactuals can be leveraged both for explaining a classifier and for bias mitigation.
format Preprint
id arxiv_https___arxiv_org_abs_2402_00711
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Explaining Text Classifiers with Counterfactual Representations
Lemberger, Pirmin
Saillenfest, Antoine
Machine Learning
Computation and Language
62Fxx
One well motivated explanation method for classifiers leverages counterfactuals which are hypothetical events identical to real observations in all aspects except for one feature. Constructing such counterfactual poses specific challenges for texts, however, as some attribute values may not necessarily align with plausible real-world events. In this paper we propose a simple method for generating counterfactuals by intervening in the space of text representations which bypasses this limitation. We argue that our interventions are minimally disruptive and that they are theoretically sound as they align with counterfactuals as defined in Pearl's causal inference framework. To validate our method, we conducted experiments first on a synthetic dataset and then on a realistic dataset of counterfactuals. This allows for a direct comparison between classifier predictions based on ground truth counterfactuals - obtained through explicit text interventions - and our counterfactuals, derived through interventions in the representation space. Eventually, we study a real world scenario where our counterfactuals can be leveraged both for explaining a classifier and for bias mitigation.
title Explaining Text Classifiers with Counterfactual Representations
topic Machine Learning
Computation and Language
62Fxx
url https://arxiv.org/abs/2402.00711