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 Statistical Learning


EnCoBo: Energy-Guided Concept Bottlenecks for Interpretable Generation

arXiv.org Artificial Intelligence

Concept Bottleneck Models (CBMs) provide interpretable decision-making through explicit, human-understandable concepts. However, existing generative CBMs often rely on auxiliary visual cues at the bottleneck, which undermines interpretability and intervention capabilities. We propose EnCoBo, a post-hoc concept bottleneck for generative models that eliminates auxiliary cues by constraining all representations to flow solely through explicit concepts. Unlike autoencoder-based approaches that inherently rely on black-box decoders, EnCoBo leverages a decoder-free, energy-based framework that directly guides generation in the latent space. Guided by diffusion-scheduled energy functions, EnCoBo supports robust post-hoc interventions-such as concept composition and negation-across arbitrary concepts. Experiments on CelebA-HQ and CUB datasets showed that EnCoBo improved concept-level human intervention and interpretability while maintaining competitive visual quality.


SMART: Simulated Students Aligned with Item Response Theory for Question Difficulty Prediction

arXiv.org Artificial Intelligence

Item (question) difficulties play a crucial role in educational assessments, enabling accurate and efficient assessment of student abilities and personalization to maximize learning outcomes. Traditionally, estimating item difficulties can be costly, requiring real students to respond to items, followed by fitting an item response theory (IRT) model to get difficulty estimates. This approach cannot be applied to the cold-start setting for previously unseen items either. In this work, we present SMART (Simulated Students Aligned with IRT), a novel method for aligning simulated students with instructed ability, which can then be used in simulations to predict the difficulty of open-ended items. We achieve this alignment using direct preference optimization (DPO), where we form preference pairs based on how likely responses are under a ground-truth IRT model. We perform a simulation by generating thousands of responses, evaluating them with a large language model (LLM)-based scoring model, and fit the resulting data to an IRT model to obtain item difficulty estimates. Through extensive experiments on two real-world student response datasets, we show that SMART outperforms other item difficulty prediction methods by leveraging its improved ability alignment.


A Plea for History and Philosophy of Statistics and Machine Learning

arXiv.org Artificial Intelligence

The integration of the history and philosophy of statistics was initiated at least by Hacking (1975) and advanced by Hacking (1990), Mayo (1996), and Zabell (2005), but it has not received sustained follow-up. Yet such integration is more urgent than ever, as the recent success of artificial intelligence has been driven largely by machine learning -- a field historically developed alongside statistics. Today, the boundary between statistics and machine learning is increasingly blurred. What we now need is integration, twice over: of history and philosophy, and of two fields they engage -- statistics and machine learning. I present a case study of a philosophical idea in machine learning (and in formal epistemology) whose root can be traced back to an often under-appreciated insight in Neyman and Pearson's 1936 work (a follow-up to their 1933 classic). This leads to the articulation of an epistemological principle -- largely implicit in, but shared by, the practices of frequentist statistics and machine learning -- which I call achievabilism: the thesis that the correct standard for assessing non-deductive inference methods should not be fixed, but should instead be sensitive to what is achievable in specific problem contexts. Another integration also emerges at the level of methodology, combining two ends of the philosophy of science spectrum: history and philosophy of science on the one hand, and formal epistemology on the other hand.


The Mean of Multi-Object Trajectories

arXiv.org Artificial Intelligence

This paper introduces the concept of a mean for trajectories and multi-object trajectories (defined as sets or multi-sets of trajectories) along with algorithms for computing them. Specifically, we use the Fréchet mean, and metrics based on the optimal sub-pattern assignment (OSPA) construct, to extend the notion of average from vectors to trajectories and multi-object trajectories. Further, we develop efficient algorithms to compute these means using greedy search and Gibbs sampling. Using distributed multi-object tracking as an application, we demonstrate that the Fréchet mean approach to multi-object trajectory consensus significantly outperforms state-of-the-art distributed multi-object tracking methods.


Attractor-merging Crises and Intermittency in Reservoir Computing

arXiv.org Artificial Intelligence

Reservoir computing can embed attractors into random neural networks (RNNs), generating a ``mirror'' of a target attractor because of its inherent symmetrical constraints. In these RNNs, we report that an attractor-merging crisis accompanied by intermittency emerges simply by adjusting the global parameter. We further reveal its underlying mechanism through a detailed analysis of the phase-space structure and demonstrate that this bifurcation scenario is intrinsic to a general class of RNNs, independent of training data.


Potential Indicator for Continuous Emotion Arousal by Dynamic Neural Synchrony

arXiv.org Artificial Intelligence

The need for automatic and high-quality emotion annotation is paramount in applications such as continuous emotion rec ognition and video highlight detection, yet achieving this through manu al human annotations is challenging. Inspired by inter-subject corre lation (ISC) utilized in neuroscience, this study introduces a novel Electr oencephalog-raphy (EEG) based ISC methodology that leverages a single-e lectrode and feature-based dynamic approach. Our contributions are three folds: Firstly, we reidentify two potent emotion features suitabl e for classifying emotions--first-order difference (FD) an differential entrop y (DE). Secondly, through the use of overall correlation analysis, we d emonstrate the heterogeneous synchronized performance of electrodes. Th is performance aligns with neural emotion patterns established in prior st udies, thus validating the effectiveness of our approach. Thirdly, by emplo ying a sliding window correlation technique, we showcase the significant c onsistency of dynamic ISCs across various features or key electrodes in ea ch analyzed film clip. Our findings indicate the method's reliability in c apturing consistent, dynamic shared neural synchrony among individual s, triggered by evocative film stimuli. This underscores the potential of our approach to serve as an indicator of continuous human emotion arousal . The implications of this research are significant for advancement s in affective computing and the broader neuroscience field, suggesting a s treamlined and effective tool for emotion analysis in real-world applic ations. 2 G. Pan et al.


Decentralized Optimization with Topology-Independent Communication

arXiv.org Artificial Intelligence

Distributed optimization requires nodes to coordinate, yet full synchronization scales poorly. When $n$ nodes collaborate through $m$ pairwise regularizers, standard methods demand $\mathcal{O}(m)$ communications per iteration. This paper proposes randomized local coordination: each node independently samples one regularizer uniformly and coordinates only with nodes sharing that term. This exploits partial separability, where each regularizer $G_j$ depends on a subset $S_j \subseteq \{1,\ldots,n\}$ of nodes. For graph-guided regularizers where $|S_j|=2$, expected communication drops to exactly 2 messages per iteration. This method achieves $\tilde{\mathcal{O}}(\varepsilon^{-2})$ iterations for convex objectives and under strong convexity, $\mathcal{O}(\varepsilon^{-1})$ to an $\varepsilon$-solution and $\mathcal{O}(\log(1/\varepsilon))$ to a neighborhood. Replacing the proximal map of the sum $\sum_j G_j$ with the proximal map of a single randomly selected regularizer $G_j$ preserves convergence while eliminating global coordination. Experiments validate both convergence rates and communication efficiency across synthetic and real-world datasets.


Defining, Understanding, and Detecting Online Toxicity: Challenges and Machine Learning Approaches

arXiv.org Artificial Intelligence

Online toxic content has grown into a pervasive phenomenon, intensifying during times of crisis, elections, and social unrest. A significant amount of research has been focused on detecting or analyzing toxic content using machine-learning approaches. The proliferation of toxic content across digital platforms has spurred extensive research into automated detection mechanisms, primarily driven by advances in machine learning and natural language processing. Overall, the present study represents the synthesis of 140 publications on different types of toxic content on digital platforms. We present a comprehensive overview of the datasets used in previous studies focusing on definitions, data sources, challenges, and machine learning approaches employed in detecting online toxicity, such as hate speech, offensive language, and harmful discourse. The dataset encompasses content in 32 languages, covering topics such as elections, spontaneous events, and crises. We examine the possibility of using existing cross-platform data to improve the performance of classification models. We present the recommendations and guidelines for new research on online toxic consent and the use of content moderation for mitigation. Finally, we present some practical guidelines to mitigate toxic content from online platforms.


Parametrized Quantum Circuit Learning for Quantum Chemical Applications

arXiv.org Artificial Intelligence

Despite numerous proposed applications, there remains limited exploration of datasets relevant to quantum chemistry. In this study, we investigate the potential benefits and limitations of PQCs on two chemically meaningful datasets: (1) the BSE49 dataset, containing bond separation energies for 49 different classes of chemical bonds, and (2) a dataset of water conformations, where coupled-cluster singles and doubles (CCSD) wavefunctions are predicted from lower-level electronic structure methods using the data-driven coupled-cluster (DDCC) approach. We construct a comprehensive set of 168 PQCs by combining 14 data encoding strategies with 12 variational ansätze, and evaluate their performance on circuits with 5 and 16 qubits. Our initial analysis examines the impact of circuit structure on model performance using state-vector simulations. We then explore how circuit depth and training set size influence model performance. Finally, we assess the performance of the best-performing PQCs on current quantum hardware, using both noisy simulations ("fake" backends) and real quantum devices. Our findings underscore the challenges of applying PQCs to chemically relevant problems that are straightforward for classical machine learning methods but remain non-trivial for quantum approaches. 2 1 Introduction In recent years, machine learning (ML) has emerged as a popular tool in chemistry to reveal new patterns in data, provide new insights beyond simple models, accelerate computations, and analyze chemical space. For computational chemists, the primary goal of applying ML is often to circumvent the explicit calculation of molecular properties, which can be computationally expensive for large datasets.


KCluster: An LLM-based Clustering Approach to Knowledge Component Discovery

arXiv.org Artificial Intelligence

Educators evaluate student knowledge using knowledge component (KC) models that map assessment questions to KCs. Still, designing KC models for large question banks remains an insurmountable challenge for instructors who need to analyze each question by hand. The growing use of Generative AI in education is expected only to aggravate this chronic deficiency of expert-designed KC models, as course engineers designing KCs struggle to keep up with the pace at which questions are generated. In this work, we propose KCluster, a novel KC discovery algorithm based on identifying clusters of congruent questions according to a new similarity metric induced by a large language model (LLM). We demonstrate in three datasets that an LLM can create an effective metric of question similarity, which a clustering algorithm can use to create KC models from questions with minimal human effort. Combining the strengths of LLM and clustering, KCluster generates descriptive KC labels and discovers KC models that predict student performance better than the best expert-designed models available. In anticipation of future work, we illustrate how KCluster can reveal insights into difficult KCs and suggest improvements to instruction.