Explanation & Argumentation
Behaviour Trees for Creating Conversational Explanation Experiences
Wijekoon, Anjana, Corsar, David, Wiratunga, Nirmalie
This paper presented an XAI system specification and an interactive dialogue model to facilitate the creation of Explanation Experiences (EE). Such specifications combine the knowledge of XAI, domain and system experts of a use case to formalise target user groups and their explanation needs and to implement explanation strategies to address those needs. Formalising the XAI system promotes the reuse of existing explainers and known explanation needs that can be refined and evolved over time using user evaluation feedback. The abstract EE dialogue model formalised the interactions between a user and an XAI system. The resulting EE conversational chatbot is personalised to an XAI system at run-time using the knowledge captured in its XAI system specification. This seamless integration is enabled by using Behaviour Trees (BT) to conceptualise both the EE dialogue model and the explanation strategies. In the evaluation, we discussed several desirable properties of using BTs over traditionally used STMs or FSMs. BTs promote the reusability of dialogue components through the hierarchical nature of the design. Sub-trees are modular, i.e. a sub-tree is responsible for a specific behaviour, which can be designed in different levels of granularity to improve human interpretability. The EE dialogue model consists of abstract behaviours needed to capture EE, accordingly, it can be implemented as a conversational, graphical or text-based interface which caters to different domains and users. There is a significant computational cost when using BTs for modelling dialogue, which we mitigate by using memory. Overall, we find that the ability to create robust conversational pathways dynamically makes BTs a good candidate for designing and implementing conversation for creating explanation experiences.
Interview with Katharina Weitz and Chi Tai Dang: Do we need explainable AI in companies?
In their project report paper Do We Need Explainable AI in Companies? Investigation of Challenges, Expectations, and Chances from Employees' Perspective, Katharina Weitz, Chi Tai Dang and Elisabeth André investigated employees' specific needs and attitudes towards AI. In this interview, Katharina and Chi Tai tell us more about this work. Our paper examines the current state of AI use in companies. It is particularly important to us to capture the perspective of employees.
Mapping Knowledge Representations to Concepts: A Review and New Perspectives
Holmberg, Lars, Davidsson, Paul, Linde, Per
The success of neural networks builds to a large extent on their ability to create internal knowledge representations from real-world high-dimensional data, such as images, sound, or text. Approaches to extract and present these representations, in order to explain the neural network's decisions, is an active and multifaceted research field. To gain a deeper understanding of a central aspect of this field, we have performed a targeted review focusing on research that aims to associate internal representations with human understandable concepts. In doing this, we added a perspective on the existing research by using primarily deductive nomological explanations as a proposed taxonomy. We find this taxonomy and theories of causality, useful for understanding what can be expected, and not expected, from neural network explanations. The analysis additionally uncovers an ambiguity in the reviewed literature related to the goal of model explainability; is it understanding the ML model or, is it actionable explanations useful in the deployment domain?
Machine Learning in Transaction Monitoring: The Prospect of xAI
Gerlings, Julie, Constantiou, Ioanna
Banks hold a societal responsibility and regulatory requirements to mitigate the risk of financial crimes. Risk mitigation primarily happens through monitoring customer activity through Transaction Monitoring (TM). Recently, Machine Learning (ML) has been proposed to identify suspicious customer behavior, which raises complex socio-technical implications around trust and explainability of ML models and their outputs. However, little research is available due to its sensitivity. We aim to fill this gap by presenting empirical research exploring how ML supported automation and augmentation affects the TM process and stakeholders' requirements for building eXplainable Artificial Intelligence (xAI). Our study finds that xAI requirements depend on the liable party in the TM process which changes depending on augmentation or automation of TM. Context-relatable explanations can provide much-needed support for auditing and may diminish bias in the investigator's judgement. These results suggest a use case-specific approach for xAI to adequately foster the adoption of ML in TM.
Why 'Explainable AI' Can Benefit Business - The New Stack
If you've ever gotten a letter from a bank that explained how different financial issues influenced a credit application, you've seen explainable AI at work -- a computer used math and a set of complex formulas to calculate a score and determine whether to approve or deny your application. In making that decision, some data points were either more or less important. Maybe your long history of on-time payments or your low amount of debt contributed to your application's approval. Similarly, explainable AI shows humans how it arrived at a decision by evaluating different inputs in its calculations. While that might sound obscure or only relevant to the most hardcore data people, explainable AI brings significant business advantages that anyone interested in applying AI should consider.
Detection, Explanation and Filtering of Cyber Attacks Combining Symbolic and Sub-Symbolic Methods
Himmelhuber, Anna, Dold, Dominik, Grimm, Stephan, Zillner, Sonja, Runkler, Thomas
Machine learning (ML) on graph-structured data has recently received deepened interest in the context of intrusion detection in the cybersecurity domain. Due to the increasing amounts of data generated by monitoring tools as well as more and more sophisticated attacks, these ML methods are gaining traction. Knowledge graphs and their corresponding learning techniques such as Graph Neural Networks (GNNs) with their ability to seamlessly integrate data from multiple domains using human-understandable vocabularies, are finding application in the cybersecurity domain. However, similar to other connectionist models, GNNs are lacking transparency in their decision making. This is especially important as there tend to be a high number of false positive alerts in the cybersecurity domain, such that triage needs to be done by domain experts, requiring a lot of man power. Therefore, we are addressing Explainable AI (XAI) for GNNs to enhance trust management by exploring combining symbolic and sub-symbolic methods in the area of cybersecurity that incorporate domain knowledge. We experimented with this approach by generating explanations in an industrial demonstrator system. The proposed method is shown to produce intuitive explanations for alerts for a diverse range of scenarios. Not only do the explanations provide deeper insights into the alerts, but they also lead to a reduction of false positive alerts by 66% and by 93% when including the fidelity metric.
Causal Explanations of Structural Causal Models
Zečević, Matej, Dhami, Devendra Singh, Rothkopf, Constantin A., Kersting, Kristian
In explanatory interactive learning (XIL) the user queries the learner, then the learner explains its answer to the user and finally the loop repeats. XIL is attractive for two reasons, (1) the learner becomes better and (2) the user's trust increases. For both reasons to hold, the learner's explanations must be useful to the user and the user must be allowed to ask useful questions. Ideally, both questions and explanations should be grounded in a causal model since they avoid spurious fallacies. Ultimately, we seem to seek a causal variant of XIL. The question part on the user's end we believe to be solved since the user's mental model can provide the causal model. But how would the learner provide causal explanations? In this work we show that existing explanation methods are not guaranteed to be causal even when provided with a Structural Causal Model (SCM). Specifically, we use the popular, proclaimed causal explanation method CXPlain to illustrate how the generated explanations leave open the question of truly causal explanations. Thus as a step towards causal XIL, we propose a solution to the lack of causal explanations. We solve this problem by deriving from first principles an explanation method that makes full use of a given SCM, which we refer to as SC$\textbf{E}$ ($\textbf{E}$ standing for explanation). Since SCEs make use of structural information, any causal graph learner can now provide human-readable explanations. We conduct several experiments including a user study with 22 participants to investigate the virtue of SCE as causal explanations of SCMs.
VCNet: A self-explaining model for realistic counterfactual generation
Guyomard, Victor, Fessant, Françoise, Guyet, Thomas, Bouadi, Tassadit, Termier, Alexandre
Improvements of machine learning techniques for decision systems has led to the rise of applications in various domains such as healthcare, credit or justice. The eventual sensitivity of such domains, as well as the black-box nature of the algorithms, has motivated the need for methods that explain why some prediction was made. For example, if a person's loan is rejected as a result of a model decision, the bank must be able to explain why. In such a context, it might be interesting to provide an explanation of what that person should change to influence the model's decision. As suggested by Wachter et al. [27], one way to build this type of explanation is through the use of counterfactual explanations. A counterfactual is defined as the smallest modification of feature values that changes the prediction of a model to a given output. In addition, the explanation also provides important feedback to the user. In the context of a denied credit, a counterfactual is a close individual for whom his credit is accepted and the feature modifications suggested by a counterfactual acts as recourse for the user. For privacy reason or simply because there is no similar individual with an opposite decision, we aim to generate synthetic individuals as counterfactuals.
Context-dependent Explainability and Contestability for Trustworthy Medical Artificial Intelligence: Misclassification Identification of Morbidity Recognition Models in Preterm Infants
Guzey, Isil, Ucar, Ozlem, Ciftdemir, Nukhet Aladag, Acunas, Betul
Although machine learning (ML) models of AI achieve high performances in medicine, they are not free of errors. Empowering clinicians to identify incorrect model recommendations is crucial for engendering trust in medical AI. Explainable AI (XAI) aims to address this requirement by clarifying AI reasoning to support the end users. Several studies on biomedical imaging achieved promising results recently. Nevertheless, solutions for models using tabular data are not sufficient to meet the requirements of clinicians yet. This paper proposes a methodology to support clinicians in identifying failures of ML models trained with tabular data. We built our methodology on three main pillars: decomposing the feature set by leveraging clinical context latent space, assessing the clinical association of global explanations, and Latent Space Similarity (LSS) based local explanations. We demonstrated our methodology on ML-based recognition of preterm infant morbidities caused by infection. The risk of mortality, lifelong disability, and antibiotic resistance due to model failures was an open research question in this domain. We achieved to identify misclassification cases of two models with our approach. By contextualizing local explanations, our solution provides clinicians with actionable insights to support their autonomy for informed final decisions.
Counterfactual Explanations for Misclassified Images: How Human and Machine Explanations Differ
Delaney, Eoin, Pakrashi, Arjun, Greene, Derek, Keane, Mark T.
Counterfactual explanations have emerged as a popular solution for the eXplainable AI (XAI) problem of elucidating the predictions of black-box deep-learning systems due to their psychological validity, flexibility across problem domains and proposed legal compliance. While over 100 counterfactual methods exist, claiming to generate plausible explanations akin to those preferred by people, few have actually been tested on users ($\sim7\%$). So, the psychological validity of these counterfactual algorithms for effective XAI for image data is not established. This issue is addressed here using a novel methodology that (i) gathers ground truth human-generated counterfactual explanations for misclassified images, in two user studies and, then, (ii) compares these human-generated ground-truth explanations to computationally-generated explanations for the same misclassifications. Results indicate that humans do not "minimally edit" images when generating counterfactual explanations. Instead, they make larger, "meaningful" edits that better approximate prototypes in the counterfactual class.