One of the main challenges of AI and automation in healthcare is ensuring that experts understand and trust the system's decisions. Providing insights into model decisions is crucial for fostering transparency, accountability, and trust. Researchers and R&D departments work with diverse and variable data types depending on their projects, necessitating different Explainable AI (XAI) methods. For instance, image data might require rule-extraction or GradCAM visualizations, while tabular data might be best explained using SHAP, which offers solid theoretical foundations and both local and global explanations. This variety increases the complexity of the task, as multiple explainability methods must be tested and applied to find the most suitable ones.
Automated creation of explainability pipelines is essential. Integrating XAI effectively in digital health data is crucial for precision medicine, helping to optimize patient healthcare and improve predictive modeling. Automated pipelines allow researchers to leverage XAI in their respective fields, driving impactful research while lowering the entry barrier to this powerful technology. With automated pipelines, researchers can focus on their core research areas without needing to stay updated on advancements in AI or the niche field of XAI, ensuring that AI systems remain transparent and trustworthy. Additionally, clinical validation and quality assessment of XAI methods are vital for ensuring the reliability and acceptance of AI models in healthcare.
By incorporating Explainable AI, AICU ensures that researchers understand the "why" and "how" behind AI-driven insights, fostering trust and facilitating informed, transparent, and equitable medical research.
Captum, introduced by Narine Kokhlikyan et al., is a unified and generic model interpretability library for PyTorch that significantly enhances the explainability of AI models. Captum includes implementations of various gradient and perturbation-based attribution algorithms, such as Integrated Gradients, DeepLift, SHAP, and GradCAM, making it a versatile tool for explaining both classification and non-classification models.
Key features of Captum include:
By incorporating Captum, researchers can leverage a robust and scalable explainability tool that supports various attribution methods and provides comprehensive evaluation metrics like infidelity and maximum sensitivity, ensuring the reliability of model explanations.
SHAP (SHapley Additive exPlanations), introduced by Scott M. Lundberg and Su-In Lee in their paper "A Unified Approach to Interpreting Model Predictions," is a powerful tool for interpretable machine learning based on game theory (Lundberg, 2017). SHAP provides a unified approach to explaining the output of any machine learning model by connecting optimal credit allocation with local explanations using Shapley values from game theory and their related extensions.
Key features of SHAP include:
SHAP approximates Shapley values using methods like Kernel SHAP, which uses a weighting kernel for the approximation, and DeepSHAP, which leverages DeepLift for approximation in deep learning models. By incorporating SHAP, researchers and practitioners can gain a deeper understanding of their models, ensuring more transparent and accountable AI systems.
LIME (Local Interpretable Model-agnostic Explanations), introduced by Marco Tulio Ribeiro, Sameer Singh, and Carlos Guestrin in their paper "Why Should I Trust You?": Explaining the Predictions of Any Classifier," is an innovative technique for explaining individual predictions of black box machine learning models (Ribeiro, 2016). LIME approximates the local behavior of a model by fitting a simple, interpretable model around each prediction, providing insights into which features are most influential in the decision-making process.
Key features of LIME include:
LIME modifies a single data sample by tweaking feature values and observes the resulting impact on the output. It performs the role of an "explainer" by providing a set of explanations representing the contribution of each feature to a prediction for a single sample, offering a form of local interpretability.
Grad-CAM (Gradient-weighted Class Activation Mapping), introduced by Ramprasaath R. Selvaraju and colleagues in their ICCV 2017 paper "Grad-CAM: Visual Explanations from Deep Networks via Gradient-based Localization," is a technique designed to provide visual explanations for decisions made by convolutional neural networks (CNNs) (Selvaraju, 2017). Grad-CAM uses the gradients of target outputs flowing into the final convolutional layer to produce a heatmap that highlights important regions in the input image, revealing the model’s focus areas.
Key features of Grad-CAM include:
Grad-CAM is particularly useful for applications in computer vision, where visual explanations can provide valuable insights into the decision-making process of deep learning models. It also lends insights into failure modes, is robust to adversarial images, and helps identify dataset biases. And alternative to Grad-Cam are Efficient Saliency Maps for Explainable AI, introduced by T. Nathan Mundhenk, Barry Y. Chen, and Gerald Friedland in their 2019 paper.
ProtoPNet (Prototypical Part Network), introduced by Chaofan Chen et al. in their paper "This Looks Like That: Deep Learning for Interpretable Image Recognition," is a novel deep network architecture designed to provide interpretable image classification (Chen, 2019). ProtoPNet reasons in a way that is qualitatively similar to how experts like ornithologists or physicians explain challenging image classification tasks by dissecting the image and pointing out prototypical aspects of one class or another.
Key features of ProtoPNet include:
ProtoPNet has been demonstrated on datasets like CUB-200-2011 and Stanford Cars, showing that it can achieve high accuracy while providing clear, interpretable insights into model decisions. This makes ProtoPNet a valuable tool for domains where understanding the rationale behind image classifications is critical, such as healthcare and wildlife conservation. By dissecting images and using prototypical parts, ProtoPNet mimics human reasoning, enhancing trust and transparency in AI-driven image recognition tasks.
OmniXAI (short for Omni eXplainable AI) is an open-source Python library designed to provide comprehensive explainable AI (XAI) capabilities. Developed by Wenzhuo Yang, Hung Le, Tanmay Laud, Silvio Savarese, and Steven C. H. Hoi, OmniXAI aims to be a one-stop solution for data scientists, ML researchers, and practitioners who need to understand and interpret the decisions made by machine learning models (Yang, 2022). This versatile library supports multiple data types (tabular, images, texts, time-series) and various machine learning models (traditional ML in Scikit-learn and deep learning models in PyTorch/TensorFlow). OmniXAI integrates a wide range of explanation methods, including model-specific and model-agnostic techniques like feature-attribution, counterfactual, and gradient-based explanations. It offers a user-friendly unified interface for generating explanations with minimal coding and includes a GUI dashboard for visualizing different explanations, providing deeper insights into model decisions. This makes OmniXAI an invaluable tool for enhancing transparency and trust in AI systems across various stages of the ML process, from data exploration and feature engineering to model development and decision-making.
There is another approach to explainability in AI: Why use black box models at all? There are numerous interpretable models and out-of-the-box machine learning models available that can be used instead. In her influential paper, Cynthia Rudin argues against the reliance on black box machine learning models for high-stakes decision-making in fields like healthcare and criminal justice (Rudin, 2018). She emphasizes that the current trend of developing methods to explain these opaque models is inadequate and potentially harmful.
Rudin advocates for a paradigm shift towards designing inherently interpretable models from the outset. This approach mitigates the risks associated with black box models, which include perpetuating bad practices and causing significant societal harm. The manuscript discusses the fundamental differences between explaining black boxes and using interpretable models, highlighting the critical need to avoid explainable black boxes in high-stakes scenarios.
Rudin identifies the challenges of creating interpretable machine learning models and presents case studies demonstrating how interpretable models can be effectively utilized in domains such as criminal justice, healthcare, and computer vision. These examples offer a safer and more transparent alternative to black box models, ensuring decisions are understandable and justifiable.
By using interpretable models, we can foster greater trust and accountability in AI systems, especially in critical areas where decisions have far-reaching consequences. This shift not only improves the reliability of AI but also aligns with ethical standards, ensuring that technology serves society in a responsible and transparent manner.
Explainable AI (XAI) is transforming the healthcare industry by making AI models more transparent, accountable, and trustworthy. Automated explainability pipelines are crucial for integrating XAI effectively, allowing researchers to focus on their core areas while leveraging advanced AI insights. Features like rich evidence packages, model lineage, bias mitigation, model risk management, and human-AI collaboration are essential components of an effective XAI framework. By incorporating these features, AICU is paving the way for a more transparent, equitable, and efficient healthcare research environment.
Allen, 2024
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Yang, 2022
Yang, W., Le, H., Laud, T., Savarese, S., & Hoi, S. C. H. (2022). OmniXAI: A Library for Explainable AI. arXiv preprint arXiv:2206.02239. https://arxiv.org/abs/2206.02239
Rudin, 2018
Rudin, C. (2018). Stop Explaining Black Box Machine Learning Models for High Stakes Decisions and Use Interpretable Models Instead. arXiv preprint arXiv:1811.10154. https://arxiv.org/abs/1811.10154
Lundberg, 2017
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Ribeiro, 2016
Ribeiro, M. T., Singh, S., & Guestrin, C. (2016). "Why Should I Trust You?": Explaining the Predictions of Any Classifier. arXiv preprint arXiv:1602.04938. https://arxiv.org/abs/1602.04938
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Chen, 2019
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