ExplainabilityTransparencyTrustworthinesscs.LG
Evaluation of Saliency-based Explainability Method
Sam Zabdiel Sunder Samuel, Vidhya Kamakshi, Namrata Lodhi, Narayanan C Krishnan
June 24, 2021
arXiv.org
19 citations
2 influential
Key Takeaways
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Saliency maps lack rigorous human validation: While saliency-based explainability methods are widely used to show which parts of an image a CNN focuses on, most evidence supporting their value is anecdotal rather than based on systematic testing with actual users.
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Human experiments are essential for evaluating XAI: The paper demonstrates that computational tests alone are insufficient—the researchers conducted three human subject experiments to properly assess whether these visualization methods actually help people understand how AI models make decisions.
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End-user testing should be standard practice: Since humans are the intended audience for explainability tools, the paper emphasizes that XAI methods must be evaluated through direct human studies rather than relying solely on technical metrics, highlighting a gap in how explainability research is typically conducted.
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Visual explanations need empirical validation: The research suggests that intuitive-seeming explanations (like highlighting important image regions) require rigorous testing to confirm they genuinely improve human understanding and trust in AI systems, rather than assuming they work as intended.
Abstract
A particular class of Explainable AI (XAI) methods provide saliency maps to highlight part of the image a Convolutional Neural Network (CNN) model looks at to classify the image as a way to explain its working. These methods provide an intuitive way for users to understand predictions made by CNNs. Other than quantitative computational tests, the vast majority of evidence to highlight that the methods are valuable is anecdotal. Given that humans would be the end-users of such methods, we devise three human subject experiments through which we gauge the effectiveness of these saliency-based explainability methods.