Counterfactual Explanations for Multivariate Time-Series without Training Datasets (2405.18563v1)
Abstract: Machine learning (ML) methods have experienced significant growth in the past decade, yet their practical application in high-impact real-world domains has been hindered by their opacity. When ML methods are responsible for making critical decisions, stakeholders often require insights into how to alter these decisions. Counterfactual explanations (CFEs) have emerged as a solution, offering interpretations of opaque ML models and providing a pathway to transition from one decision to another. However, most existing CFE methods require access to the model's training dataset, few methods can handle multivariate time-series, and none can handle multivariate time-series without training datasets. These limitations can be formidable in many scenarios. In this paper, we present CFWoT, a novel reinforcement-learning-based CFE method that generates CFEs when training datasets are unavailable. CFWoT is model-agnostic and suitable for both static and multivariate time-series datasets with continuous and discrete features. Users have the flexibility to specify non-actionable, immutable, and preferred features, as well as causal constraints which CFWoT guarantees will be respected. We demonstrate the performance of CFWoT against four baselines on several datasets and find that, despite not having access to a training dataset, CFWoT finds CFEs that make significantly fewer and significantly smaller changes to the input time-series. These properties make CFEs more actionable, as the magnitude of change required to alter an outcome is vastly reduced.
- Machine bias. In Ethics of data and analytics, pages 254–264. Auerbach Publications, 2022.
- Counterfactual explanations for multivariate time series. In 2021 International Conference on Applied Artificial Intelligence (ICAPAI), pages 1–8. IEEE, 2021.
- Temporal rule-based counterfactual explanations for multivariate time series. In 2022 21st IEEE International Conference on Machine Learning and Applications (ICMLA), pages 1244–1249. IEEE, 2022.
- Leo Breiman. Classification and regression trees. Routledge, 2017.
- Lof: identifying density-based local outliers. In Proceedings of the 2000 ACM SIGMOD international conference on Management of data, pages 93–104, 2000.
- Instance-based counterfactual explanations for time series classification. In International Conference on Case-Based Reasoning, pages 32–47. Springer, 2021.
- Riccardo Guidotti. Counterfactual explanations and how to find them: literature review and benchmarking. Data Mining and Knowledge Discovery, pages 1–55, 2022.
- World models. arXiv preprint arXiv:1803.10122, 2018.
- Soft actor-critic: Off-policy maximum entropy deep reinforcement learning with a stochastic actor. In International conference on machine learning, pages 1861–1870. PMLR, 2018.
- Dice4el: interpreting process predictions using a milestone-aware counterfactual approach. In 2021 3rd International Conference on Process Mining (ICPM), pages 88–95. IEEE, 2021.
- Explainable artificial intelligence approaches: A survey. arXiv preprint arXiv:2101.09429, 2021.
- A survey of algorithmic recourse: definitions, formulations, solutions, and prospects. arXiv preprint arXiv:2010.04050, 2020a.
- Algorithmic recourse under imperfect causal knowledge: a probabilistic approach. Advances in neural information processing systems, 33:265–277, 2020b.
- Algorithmic recourse: from counterfactual explanations to interventions. In Proceedings of the 2021 ACM conference on fairness, accountability, and transparency, pages 353–362, 2021.
- Locally and globally explainable time series tweaking. Knowledge and Information Systems, 62(5):1671–1700, 2020.
- Examples are not enough, learn to criticize! criticism for interpretability. Advances in neural information processing systems, 29, 2016.
- Adam: A method for stochastic optimization. arXiv preprint arXiv:1412.6980, 2014.
- Auto-encoding variational bayes. arXiv preprint arXiv:1312.6114, 2013.
- A unified approach to interpreting model predictions. Advances in neural information processing systems, 30, 2017.
- A survey on bias and fairness in machine learning. ACM computing surveys (CSUR), 54(6):1–35, 2021.
- Human-level control through deep reinforcement learning. nature, 518(7540):529–533, 2015.
- Explaining machine learning classifiers through diverse counterfactual explanations. In Proceedings of the 2020 conference on fairness, accountability, and transparency, pages 607–617, 2020.
- Kevin P Murphy. Machine learning: a probabilistic perspective. MIT press, 2012.
- An intelligence in our image: The risks of bias and errors in artificial intelligence. Rand Corporation, 2017.
- Elements of causal inference: foundations and learning algorithms. The MIT Press, 2017.
- Model-agnostic and scalable counterfactual explanations via reinforcement learning. arXiv preprint arXiv:2106.02597, 2021.
- Trust region policy optimization. In International conference on machine learning, pages 1889–1897. PMLR, 2015.
- Proximal policy optimization algorithms. arXiv preprint arXiv:1707.06347, 2017.
- Mastering chess and shogi by self-play with a general reinforcement learning algorithm. arXiv preprint arXiv:1712.01815, 2017.
- Diverse counterfactual explanations for anomaly detection in time series. arXiv preprint arXiv:2203.11103, 2022.
- Cracking the black box: Distilling deep sports analytics. In Proceedings of the 26th acm sigkdd international conference on knowledge discovery & data mining, pages 3154–3162, 2020.
- Reinforcement learning: An introduction. MIT press, 2018.
- Explainable ai for time series classification: a review, taxonomy and research directions. IEEE Access, 10:100700–100724, 2022.
- Counterfactual explanations in sequential decision making under uncertainty. Advances in Neural Information Processing Systems, 34:30127–30139, 2021.
- Counterfactual explanations and algorithmic recourses for machine learning: A review. arXiv preprint arXiv:2010.10596, 2020.
- Amortized generation of sequential algorithmic recourses for black-box models. In Proceedings of the AAAI Conference on Artificial Intelligence, volume 36, pages 8512–8519, 2022.
- Counterfactual explanations without opening the black box: Automated decisions and the gdpr. Harv. JL & Tech., 31:841, 2017.
- Learning time series counterfactuals via latent space representations. In Discovery Science: 24th International Conference, DS 2021, Halifax, NS, Canada, October 11–13, 2021, Proceedings 24, pages 369–384. Springer, 2021.
- Ronald J Williams. Simple statistical gradient-following algorithms for connectionist reinforcement learning. Machine learning, 8:229–256, 1992.