Testing deep reinforcement learning (DRL) agents in safety-critical domains requires discovering diverse failure scenarios. Existing tools such as INDAGO rely on single-objective optimization focused solely on maximizing failure counts, but this does not ensure discovered scenarios are diverse or reveal distinct error types. We introduce INDAGO-Nexus, a multi-objective search approach that jointly optimizes for failure likelihood and test scenario diversity using multi-objective evolutionary algorithms with multiple diversity metrics and Pareto front selection strategies. We evaluated INDAGO-Nexus on three DRL agents: humanoid walker, self-driving car, and parking agent. On average, INDAGO-Nexus discovers up to 83% and 40% more unique failures (test effectiveness) than INDAGO in the SDC and Parking scenarios, respectively, while reducing time-to-failure by up to 67% across all agents.

We focus on explainability as a desideratum for automated decision-making systems, rather than only models. Although the explainable artificial intelligence (XAI) paradigm offers an impressive variety of solutions to increase the transparency of automated decisions, XAI contributions rarely account for the complete systems—social and institutional environments—where models operate. Our work focuses on one such system in the domain of social welfare, which increasingly turns to automated decision-making to carry out targeted digital surveillance. Specifically, we present a case study of a black-box machine learning model previously used in a major Dutch city to support its officials in the task of detecting fraud. Employing analyses established in the field of system safety, we identify five types of hazards that could have occurred after the introduction of the model. For each of them, we reason about the potential value of XAI interventions as hazard mitigation strategies. The case study illustrates how the deployment of models may impact processes that exist far upstream and downstream from their decision logic, making explainability and/or interpretability insufficient to guarantee the systems’ safe operation. In many cases, XAI techniques may only be able to reasonably address a small fraction of hazards related to the use of algorithms; several major hazards that we identify would have still posed risks if the system had relied on an interpretable model. Thus, we empirically demonstrate that the values, which lie at the heart of XAI research, such as responsibility, safety, or transparency, ultimately necessitate a broader outlook on automated decision-making systems.

Resolving Python dependency issues remains a tedious and error-prone process, forcing developers to manually trial compatible module versions and interpreter configurations. Existing automated solutions, such as knowledge-graph-based and database-driven methods, face limitations due to the variety of dependency error types, large sets of possible module versions, and conflicts among transitive dependencies. This paper investigates the use of Large Language Models (LLMs) to automatically repair dependency issues in Python programs. We propose pllm (pronounced 'plum'), a novel retrieval-augmented generation (RAG) approach that iteratively infers missing or incorrect dependencies. PLLM builds a test environment where the LLM proposes module combinations, observes execution feedback, and refines its predictions using natural language processing (NLP) to parse error messages. We evaluate PLLM on the Gistable HG2. 9K dataset, a curated collection of real-world Python programs. Using this benchmark, we explore multiple PLLM configurations, including six open-source LLMs evaluated both with and without RAG. Our findings show that RAG consistently improves fix rates, with the best performance achieved by Gemma-2 9B when combined with RAG. Compared to two state-of-the-art baselines, PyEGo and ReadPyE, PLLM achieves significantly higher fix rates; +15.97% more than ReadPyE and +21.58% more than PyEGo. Further analysis shows that PLLM is especially effective for projects with numerous dependencies and those using specialized numerical or machine-learning libraries.

Developments in the field of Artificial Intelligence (AI), and particularly large language models (LLMs), have created a 'perfect storm' for observing 'sparks' of Artificial General Intelligence (AGI) that are spurious. Like simpler models, LLMs distill meaningful representations in their latent embeddings that have been shown to correlate with external variables. Nonetheless, the correlation of such representations has often been linked to human-like intelligence in the latter but not the former. We probe models of varying complexity including random projections, matrix decompositions, deep autoencoders and transformers: all of them successfully distill information that can be used to predict latent or external variables and yet none of them have previously been linked to AGI. We argue and empirically demonstrate that the finding of meaningful patterns in latent spaces of models cannot be seen as evidence in favor of AGI. Additionally, we review literature from the social sciences that shows that humans are prone to seek such patterns and anthropomorphize. We conclude that both the methodological setup and common public image of AI are ideal for the misinterpretation that correlations between model representations and some variables of interest are 'caused' by the model's understanding of underlying 'ground truth' relationships. We, therefore, call for the academic community to exercise extra caution, and to be keenly aware of principles of academic integrity, in interpreting and communicating about AI research outcomes.

Counterfactual explanations offer an intuitive and straightforward way to explain black-box models and offer algorithmic recourse to individuals. To address the need for plausible explanations, existing work has primarily relied on surrogate models to learn how the input data is distributed. This effectively reallocates the task of learning realistic explanations for the data from the model itself to the surrogate. Consequently, the generated explanations may seem plausible to humans but need not necessarily describe the behaviour of the black-box model faithfully. We formalize this notion of faithfulness through the introduction of a tailored evaluation metric and propose a novel algorithmic framework for generating Energy-Constrained Conformal Counterfactuals that are only as plausible as the model permits. Through extensive empirical studies, we demonstrate that ECCCo reconciles the need for faithfulness and plausibility. In particular, we show that for models with gradient access, it is possible to achieve state-of-the-art performance without the need for surrogate models. To do so, our framework relies solely on properties defining the black-box model itself by leveraging recent advances in energy-based modelling and conformal prediction. To our knowledge, this is the first venture in this direction for generating faithful counterfactual explanations. Thus, we anticipate that ECCCo can serve as a baseline for future research. We believe that our work opens avenues for researchers and practitioners seeking tools to better distinguish trustworthy from unreliable models.

Machine Learning (ML) models influence all aspects of our lives. They also commonly are integrated in recommender systems, which facilitate users’ decision-making processes in various scenarios, such as e-commerce, social media, news and online learning. Training performed on large volumes of data is what ultimately drives such systems to provide meaningful recommendations. However, a lack of standardized practices has been observed when it comes to data collection and annotation methods for ML datasets. This research paper systematically identifies and synthesizes the state of standardization with regard to data collection and annotation reporting in the recommender systems domain, through a systematic literature view into the 100 most-cited recommender systems papers from the most impactful venues within the Computing and Information Technology field. Multiple facets of the employed techniques are touched upon, such as reported human annotations and annotator diversity, label quality, and the public availability of training datasets. Recurrent use of just a few benchmark datasets, poor documentation practices, and reproducibility issues in experiments are some of the most striking findings uncovered by this study. We discuss the necessity of transitioning from pure reliance on algorithmic performance metrics to prioritizing data quality and fit. Finally, concerns are raised when it comes to biases and socio-psychological factors inherent in the datasets, and further exploration of embedding these early in the design of ML models is suggested.