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 Explanation & Argumentation


Brittle AI, Causal Confusion, and Bad Mental Models: Challenges and Successes in the XAI Program

arXiv.org Artificial Intelligence

The advances in artificial intelligence enabled by deep learning architectures are undeniable. In several cases, deep neural network driven models have surpassed human level performance in benchmark autonomy tasks. The underlying policies for these agents, however, are not easily interpretable. In fact, given their underlying deep models, it is impossible to directly understand the mapping from observations to actions for any reasonably complex agent. Producing this supporting technology to "open the black box" of these AI systems, while not sacrificing performance, was the fundamental goal of the DARPA XAI program. In our journey through this program, we have several "big picture" takeaways: 1) Explanations need to be highly tailored to their scenario; 2) many seemingly high performing RL agents are extremely brittle and are not amendable to explanation; 3) causal models allow for rich explanations, but how to present them isn't always straightforward; and 4) human subjects conjure fantastically wrong mental models for AIs, and these models are often hard to break. This paper discusses the origins of these takeaways, provides amplifying information, and suggestions for future work.


NVIDIA Blog: What is Explainable AI?

#artificialintelligence

Banks use AI to determine whether to extend credit, and how much, to customers. Radiology departments deploy AI to help distinguish between healthy tissue and tumors. And HR teams employ it to work out which of hundreds of resumes should be sent on to recruiters. These are just a few examples of how AI is being adopted across industries. And with so much at stake, businesses and governments adopting AI and machine learning are increasingly being pressed to lift the veil on how their AI models make decisions.


A general approach for Explanations in terms of Middle Level Features

arXiv.org Artificial Intelligence

Nowadays, it is growing interest to make Machine Learning (ML) systems more understandable and trusting to general users. Thus, generating explanations for ML system behaviours that are understandable to human beings is a central scientific and technological issue addressed by the rapidly growing research area of eXplainable Artificial Intelligence (XAI). Recently, it is becoming more and more evident that new directions to create better explanations should take into account what a good explanation is to a human user, and consequently, develop XAI solutions able to provide user-centred explanations. This paper suggests taking advantage of developing an XAI general approach that allows producing explanations for an ML system behaviour in terms of different and user-selected input features, i.e., explanations composed of input properties that the human user can select according to his background knowledge and goals. To this end, we propose an XAI general approach which is able: 1) to construct explanations in terms of input features that represent more salient and understandable input properties for a user, which we call here Middle-Level input Features (MLFs), 2) to be applied to different types of MLFs. We experimentally tested our approach on two different datasets and using three different types of MLFs. The results seem encouraging.


Amortized Generation of Sequential Counterfactual Explanations for Black-box Models

arXiv.org Artificial Intelligence

Explainable machine learning (ML) has gained traction in recent years due to the increasing adoption of ML-based systems in many sectors. Counterfactual explanations (CFEs) provide ``what if'' feedback of the form ``if an input datapoint were $x'$ instead of $x$, then an ML-based system's output would be $y'$ instead of $y$.'' CFEs are attractive due to their actionable feedback, amenability to existing legal frameworks, and fidelity to the underlying ML model. Yet, current CFE approaches are single shot -- that is, they assume $x$ can change to $x'$ in a single time period. We propose a novel stochastic-control-based approach that generates sequential CFEs, that is, CFEs that allow $x$ to move stochastically and sequentially across intermediate states to a final state $x'$. Our approach is model agnostic and black box. Furthermore, calculation of CFEs is amortized such that once trained, it applies to multiple datapoints without the need for re-optimization. In addition to these primary characteristics, our approach admits optional desiderata such as adherence to the data manifold, respect for causal relations, and sparsity -- identified by past research as desirable properties of CFEs. We evaluate our approach using three real-world datasets and show successful generation of sequential CFEs that respect other counterfactual desiderata.


How explainable AI can help uplift modern businesses

#artificialintelligence

Explainable AI (XAI) fully describes an AI model, its expected impact and any potential biases. It helps you understand the steps taken by an AI technique to arrive at a decision. In this article, we will take a look at XAI in detail and explore how you can implement it in your organisation. "About half (46%) of South African companies indicate that they are already implementing AI within their organisations." Why is explainable AI important for your business?


Towards an Explanation Space to Align Humans and Explainable-AI Teamwork

arXiv.org Artificial Intelligence

Providing meaningful and actionable explanations to end-users is a fundamental prerequisite for implementing explainable intelligent systems in the real world. Explainability is a situated interaction between a user and the AI system rather than being static design principles. The content of explanations is context-dependent and must be defined by evidence about the user and its context. This paper seeks to operationalize this concept by proposing a formative architecture that defines the explanation space from a user-inspired perspective. The architecture comprises five intertwined components to outline explanation requirements for a task: (1) the end-users mental models, (2) the end-users cognitive process, (3) the user interface, (4) the human-explainer agent, and the (5) agent process. We first define each component of the architecture. Then we present the Abstracted Explanation Space, a modeling tool that aggregates the architecture's components to support designers in systematically aligning explanations with the end-users work practices, needs, and goals. It guides the specifications of what needs to be explained (content - end-users mental model), why this explanation is necessary (context - end-users cognitive process), to delimit how to explain it (format - human-explainer agent and user interface), and when should the explanations be given. We then exemplify the tool's use in an ongoing case study in the aircraft maintenance domain. Finally, we discuss possible contributions of the tool, known limitations/areas for improvement, and future work to be done.


To trust or not to trust an explanation: using LEAF to evaluate local linear XAI methods

arXiv.org Artificial Intelligence

The main objective of eXplainable Artificial Intelligence (XAI) is to provide effective explanations for black-box classifiers. The existing literature lists many desirable properties for explanations to be useful, but there is no consensus on how to quantitatively evaluate explanations in practice. Moreover, explanations are typically used only to inspect black-box models, and the proactive use of explanations as a decision support is generally overlooked. Among the many approaches to XAI, a widely adopted paradigm is Local Linear Explanations - with LIME and SHAP emerging as state-of-the-art methods. We show that these methods are plagued by many defects including unstable explanations, divergence of actual implementations from the promised theoretical properties, and explanations for the wrong label. This highlights the need to have standard and unbiased evaluation procedures for Local Linear Explanations in the XAI field. In this paper we address the problem of identifying a clear and unambiguous set of metrics for the evaluation of Local Linear Explanations. This set includes both existing and novel metrics defined specifically for this class of explanations. All metrics have been included in an open Python framework, named LEAF. The purpose of LEAF is to provide a reference for end users to evaluate explanations in a standardised and unbiased way, and to guide researchers towards developing improved explainable techniques.


Bounded logit attention: Learning to explain image classifiers

arXiv.org Artificial Intelligence

Explainable artificial intelligence is the attempt to elucidate the workings of systems too complex to be directly accessible to human cognition through suitable sideinformation referred to as "explanations". We present a trainable explanation module for convolutional image classifiers we call bounded logit attention (BLA). The BLA module learns to select a subset of the convolutional feature map for each input instance, which then serves as an explanation for the classifier's prediction. BLA overcomes several limitations of the instancewise feature selection method "learning to explain" (L2X) introduced by Chen et al. (2018): 1) BLA scales to real-world sized image classification problems, and 2) BLA offers a canonical way to learn explanations of variable size. Due to its modularity BLA lends itself to transfer learning setups and can also be employed as a post-hoc add-on to trained classifiers. Beyond explainability, BLA may serve as a general purpose method for differentiable approximation of subset selection. In a user study we find that BLA explanations are preferred over explanations generated by the popular (Grad-)CAM method (Zhou et al., 2016; Selvaraju et al., 2017).


Explainable Artificial Intelligence (xAI) Explained

#artificialintelligence

The problem that we face now with artificial intelligence (AI) is that many methods work, and we believe that for whatever is done under the hoods – we don't elaborate on the details. Yet it's very important to understand how the prediction is done, not only to understand the architecture of the method. That's why explainable AI (xAI) is becoming a hot topic today. There are many goals for an xAI model to fulfill. It's important that domain experts using a model can trust it.


Explainable AI (XAI) with SHAP - regression problem

#artificialintelligence

Model explainability becomes a basic part of the machine learning pipeline. Keeping a machine learning model as a "black box" is not an option anymore. Luckily there are tools that are evolving rapidly and becoming more popular. This guide is a practical guide for XAI analysis of SHAP open source Python package for a regression problem. SHAP (Shapley Additive Explanations) by Lundberg and Lee (2016) is a method to explain individual predictions, based on the game theoretically optimal Shapley values.