Search Results for author: Julien Horwood

Found 5 papers, 0 papers with code

Feature Attribution with Necessity and Sufficiency via Dual-stage Perturbation Test for Causal Explanation

no code implementations13 Feb 2024 Xuexin Chen, Ruichu Cai, Zhengting Huang, Yuxuan Zhu, Julien Horwood, Zhifeng Hao, Zijian Li, Jose Miguel Hernandez-Lobato

We investigate the problem of explainability in machine learning. To address this problem, Feature Attribution Methods (FAMs) measure the contribution of each feature through a perturbation test, where the difference in prediction is compared under different perturbations. However, such perturbation tests may not accurately distinguish the contributions of different features, when their change in prediction is the same after perturbation. In order to enhance the ability of FAMs to distinguish different features' contributions in this challenging setting, we propose to utilize the probability (PNS) that perturbing a feature is a necessary and sufficient cause for the prediction to change as a measure of feature importance. Our approach, Feature Attribution with Necessity and Sufficiency (FANS), computes the PNS via a perturbation test involving two stages (factual and interventional). In practice, to generate counterfactual samples, we use a resampling-based approach on the observed samples to approximate the required conditional distribution. Finally, we combine FANS and gradient-based optimization to extract the subset with the largest PNS. We demonstrate that FANS outperforms existing feature attribution methods on six benchmarks.

counterfactual

Leveraging Task Structures for Improved Identifiability in Neural Network Representations

no code implementations26 Jun 2023 Wenlin Chen, Julien Horwood, Juyeon Heo, José Miguel Hernández-Lobato

This work extends the theory of identifiability in supervised learning by considering the consequences of having access to a distribution of tasks.

Representation Learning

Molecular Design in Synthetically Accessible Chemical Space via Deep Reinforcement Learning

no code implementations29 Apr 2020 Julien Horwood, Emmanuel Noutahi

The fundamental goal of generative drug design is to propose optimized molecules that meet predefined activity, selectivity, and pharmacokinetic criteria.

Inductive Bias reinforcement-learning +1

Towards Interpretable Molecular Graph Representation Learning

no code implementations25 Sep 2019 Emmanuel Noutahi, Dominique Beani, Julien Horwood, Prudencio Tossou

Recent work in graph neural networks (GNNs) has led to improvements in molecular activity and property prediction tasks.

Drug Discovery Graph Representation Learning +1

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