Improving the Evaluation and Actionability of Explanation Methods for Multivariate Time Series Classification

Fuente: arXiv
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Main Authors: Serramazza, Davide Italo, Nguyen, Thach Le, Ifrim, Georgiana
Format: Preprint
Published: 2024
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author Serramazza, Davide Italo
Nguyen, Thach Le
Ifrim, Georgiana
author_facet Serramazza, Davide Italo
Nguyen, Thach Le
Ifrim, Georgiana
contents Explanation for Multivariate Time Series Classification (MTSC) is an important topic that is under explored. There are very few quantitative evaluation methodologies and even fewer examples of actionable explanation, where the explanation methods are shown to objectively improve specific computational tasks on time series data. In this paper we focus on analyzing InterpretTime, a recent evaluation methodology for attribution methods applied to MTSC. We showcase some significant weaknesses of the original methodology and propose ideas to improve both its accuracy and efficiency. Unlike related work, we go beyond evaluation and also showcase the actionability of the produced explainer ranking, by using the best attribution methods for the task of channel selection in MTSC. We find that perturbation-based methods such as SHAP and Feature Ablation work well across a set of datasets, classifiers and tasks and outperform gradient-based methods. We apply the best ranked explainers to channel selection for MTSC and show significant data size reduction and improved classifier accuracy.
format Preprint
id arxiv_https___arxiv_org_abs_2406_12507
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Improving the Evaluation and Actionability of Explanation Methods for Multivariate Time Series Classification
Serramazza, Davide Italo
Nguyen, Thach Le
Ifrim, Georgiana
Machine Learning
Explanation for Multivariate Time Series Classification (MTSC) is an important topic that is under explored. There are very few quantitative evaluation methodologies and even fewer examples of actionable explanation, where the explanation methods are shown to objectively improve specific computational tasks on time series data. In this paper we focus on analyzing InterpretTime, a recent evaluation methodology for attribution methods applied to MTSC. We showcase some significant weaknesses of the original methodology and propose ideas to improve both its accuracy and efficiency. Unlike related work, we go beyond evaluation and also showcase the actionability of the produced explainer ranking, by using the best attribution methods for the task of channel selection in MTSC. We find that perturbation-based methods such as SHAP and Feature Ablation work well across a set of datasets, classifiers and tasks and outperform gradient-based methods. We apply the best ranked explainers to channel selection for MTSC and show significant data size reduction and improved classifier accuracy.
title Improving the Evaluation and Actionability of Explanation Methods for Multivariate Time Series Classification
topic Machine Learning
url https://arxiv.org/abs/2406.12507