Accuracy
Scaling and renormalization in high-dimensional regression
Atanasov, Alexander, Zavatone-Veth, Jacob A., Pehlevan, Cengiz
This paper presents a succinct derivation of the training and generalization performance of a variety of high-dimensional ridge regression models using the basic tools of random matrix theory and free probability. We provide an introduction and review of recent results on these topics, aimed at readers with backgrounds in physics and deep learning. Analytic formulas for the training and generalization errors are obtained in a few lines of algebra directly from the properties of the $S$-transform of free probability. This allows for a straightforward identification of the sources of power-law scaling in model performance. We compute the generalization error of a broad class of random feature models. We find that in all models, the $S$-transform corresponds to the train-test generalization gap, and yields an analogue of the generalized-cross-validation estimator. Using these techniques, we derive fine-grained bias-variance decompositions for a very general class of random feature models with structured covariates. These novel results allow us to discover a scaling regime for random feature models where the variance due to the features limits performance in the overparameterized setting. We also demonstrate how anisotropic weight structure in random feature models can limit performance and lead to nontrivial exponents for finite-width corrections in the overparameterized setting. Our results extend and provide a unifying perspective on earlier models of neural scaling laws.
The Mystery of AI Gunshot-Detection Accuracy Is Finally Unraveling
Liz Gonzรกlez's neighborhood in East San Jose can be loud. Some of her neighbors apparently want the whole block to hear their cars, others like to light fireworks for every occasion, and occasionally there are gunshots. In February 2023, San Jose began piloting AI-powered gunshot detection technology from the company Flock Safety in several sections of the city, including Gonzalez's neighborhood. During the first four months of the pilot, Flock's gunshot detection system alerted police to 123 shooting incidents. But new data released by San Jose's Digital Privacy Office shows that only 50 percent of those alerts were actually confirmed to be gunfire, while 34 percent of them were confirmed false positives, meaning the Flock Safety system incorrectly identified other sounds--such as fireworks, construction, or cars backfiring--as shooting incidents. After Flock recalibrated its sensors in July 2023, 81 percent of alerts were confirmed gunshots, 7 percent were false alarms, and 12 percent could not be determined one way or the other.
LABOR-LLM: Language-Based Occupational Representations with Large Language Models
Du, Tianyu, Kanodia, Ayush, Brunborg, Herman, Vafa, Keyon, Athey, Susan
Many empirical studies of labor market questions rely on estimating relatively simple predictive models using small, carefully constructed longitudinal survey datasets based on hand-engineered features. Large Language Models (LLMs), trained on massive datasets, encode vast quantities of world knowledge and can be used for the next job prediction problem. However, while an off-the-shelf LLM produces plausible career trajectories when prompted, the probability with which an LLM predicts a particular job transition conditional on career history will not, in general, align with the true conditional probability in a given population. Recently, Vafa et al. (2024) introduced a transformer-based "foundation model", CAREER, trained using a large, unrepresentative resume dataset, that predicts transitions between jobs; it further demonstrated how transfer learning techniques can be used to leverage the foundation model to build better predictive models of both transitions and wages that reflect conditional transition probabilities found in nationally representative survey datasets. This paper considers an alternative where the fine-tuning of the CAREER foundation model is replaced by fine-tuning LLMs. For the task of next job prediction, we demonstrate that models trained with our approach outperform several alternatives in terms of predictive performance on the survey data, including traditional econometric models, CAREER, and LLMs with in-context learning, even though the LLM can in principle predict job titles that are not allowed in the survey data. Further, we show that our fine-tuned LLM-based models' predictions are more representative of the career trajectories of various workforce subpopulations than off-the-shelf LLM models and CAREER. We conduct experiments and analyses that highlight the sources of the gains in the performance of our models for representative predictions.
Foundation Models for Electrocardiograms
Song, Junho, Jang, Jong-Hwan, Lee, Byeong Tak, Hong, DongGyun, Kwon, Joon-myoung, Jo, Yong-Yeon
Foundation models, enhanced by self-supervised learning (SSL) techniques, represent a cutting-edge frontier in biomedical signal analysis, particularly for electrocardiograms (ECGs), crucial for cardiac health monitoring and diagnosis. This study conducts a comprehensive analysis of foundation models for ECGs by employing and refining innovative SSL methodologies - namely, generative and contrastive learning - on a vast dataset of over 1.1 million ECG samples. By customizing these methods to align with the intricate characteristics of ECG signals, our research has successfully developed foundation models that significantly elevate the precision and reliability of cardiac diagnostics. These models are adept at representing the complex, subtle nuances of ECG data, thus markedly enhancing diagnostic capabilities. The results underscore the substantial potential of SSL-enhanced foundation models in clinical settings and pave the way for extensive future investigations into their scalable applications across a broader spectrum of medical diagnostics. This work sets a benchmark in the ECG field, demonstrating the profound impact of tailored, data-driven model training on the efficacy and accuracy of medical diagnostics.
European Space Agency Benchmark for Anomaly Detection in Satellite Telemetry
Kotowski, Krzysztof, Haskamp, Christoph, Andrzejewski, Jacek, Ruszczak, Bogdan, Nalepa, Jakub, Lakey, Daniel, Collins, Peter, Kolmas, Aybike, Bartesaghi, Mauro, Martinez-Heras, Jose, De Canio, Gabriele
Machine learning has vast potential to improve anomaly detection in satellite telemetry which is a crucial task for spacecraft operations. This potential is currently hampered by a lack of comprehensible benchmarks for multivariate time series anomaly detection, especially for the challenging case of satellite telemetry. The European Space Agency Benchmark for Anomaly Detection in Satellite Telemetry (ESA-ADB) aims to address this challenge and establish a new 1 standard in the domain. It is a result of close cooperation between spacecraft operations engineers from the European Space Agency (ESA) and machine learning experts. The newly introduced ESA Anomalies Dataset contains annotated real-life telemetry from three different ESA missions, out of which two are included in ESA-ADB. Results of typical anomaly detection algorithms assessed in our novel hierarchical evaluation pipeline show that new approaches are necessary to address operators' needs. All elements of ESA-ADB are publicly available to ensure its full reproducibility.
Enabling Regional Explainability by Automatic and Model-agnostic Rule Extraction
Chen, Yu, Cui, Tianyu, Capstick, Alexander, Fletcher-Loyd, Nan, Barnaghi, Payam
In Explainable AI, rule extraction translates model knowledge into logical rules, such as IF-THEN statements, crucial for understanding patterns learned by black-box models. This could significantly aid in fields like disease diagnosis, disease progression estimation, or drug discovery. However, such application domains often contain imbalanced data, with the class of interest underrepresented. Existing methods inevitably compromise the performance of rules for the minor class to maximise the overall performance. As the first attempt in this field, we propose a model-agnostic approach for extracting rules from specific subgroups of data, featuring automatic rule generation for numerical features. This method enhances the regional explainability of machine learning models and offers wider applicability compared to existing methods. We additionally introduce a new method for selecting features to compose rules, reducing computational costs in high-dimensional spaces. Experiments across various datasets and models demonstrate the effectiveness of our methods.
Inherent Challenges of Post-Hoc Membership Inference for Large Language Models
Meeus, Matthieu, Jain, Shubham, Rei, Marek, de Montjoye, Yves-Alexandre
Large Language Models (LLMs) are often trained on vast amounts of undisclosed data, motivating the development of post-hoc Membership Inference Attacks (MIAs) to gain insight into their training data composition. However, in this paper, we identify inherent challenges in post-hoc MIA evaluation due to potential distribution shifts between collected member and non-member datasets. Using a simple bag-of-words classifier, we demonstrate that datasets used in recent post-hoc MIAs suffer from significant distribution shifts, in some cases achieving near-perfect distinction between members and non-members. This implies that previously reported high MIA performance may be largely attributable to these shifts rather than model memorization. We confirm that randomized, controlled setups eliminate such shifts and thus enable the development and fair evaluation of new MIAs. However, we note that such randomized setups are rarely available for the latest LLMs, making post-hoc data collection still required to infer membership for real-world LLMs. As a potential solution, we propose a Regression Discontinuity Design (RDD) approach for post-hoc data collection, which substantially mitigates distribution shifts. Evaluating various MIA methods on this RDD setup yields performance barely above random guessing, in stark contrast to previously reported results. Overall, our findings highlight the challenges in accurately measuring LLM memorization and the need for careful experimental design in (post-hoc) membership inference tasks.
InFiConD: Interactive No-code Fine-tuning with Concept-based Knowledge Distillation
Huang, Jinbin, He, Wenbin, Gou, Liang, Ren, Liu, Bryan, Chris
's interface consists of six coordinated views: (a) The configuration view provides an overview of the dataset and teacher model being distilled, while (b) the student performance view displays a summary of each student model's performance and highlights subsets where student and teacher models misalign. Abstract-- The emergence of large-scale pretrained models has heightened their application in various downstream tasks, yet deployment is a challenge in environments with limited computational resources. Knowledge distillation has emerged as a solution in such scenarios, whereby knowledge from large teacher models is transferred into smaller student' models, but this is a non-trivial process that traditionally requires technical expertise in AI/ML. We develop a novel knowledge distillation pipeline based on extracting text-aligned visual concepts from a concept corpus using multimodal models, and construct highly interpretable linear student models based on visual concepts that mimic a teacher model in a response-based manner. 's interface allows users to interactively fine-tune the student model by manipulating concept influences directly in the user interface. 's human-in-the-loop and visualization-driven approach enables users to effectively create and analyze student models, understand how knowledge is transferred, and efficiently perform fine-tuning operations. We discuss how this work highlights the potential of interactive and visual methods in making knowledge distillation and subsequent no-code fine-tuning more accessible and adaptable to a wider range of users with domain-specific demands. Jinbin Huang and Chris Bryan are with Arizona State Uiversity. Importantly, to serve as new initializations to fine-tune the student model for a few KD has been shown as effective even when the teacher and student epochs, effectively adapting the model based on user instructions. In particular, we are inspired by recent efforts This section provides a brief overview of knowledge distillation, and in KD interpretability that leverage visual concepts---a technique then discusses relevant related work at the intersection of visual analytics originally designed to explain model behaviors [21, 38, 43]. While 2.1 Knowledge Distillation such methods can improve KD interpretability, they primarily rely on Knowledge distillation (KD) [23] is the process of transferring knowledge automated concept extraction pipelines that generate large ensembles of from a large'teacher' PTM to a more compact'student' model.
Stacked Confusion Reject Plots (SCORE)
Hasler, Stephan, Fischer, Lydia
Machine learning is more and more applied in critical application areas like health and driver assistance. To minimize the risk of wrong decisions, in such applications it is necessary to consider the certainty of a classification to reject uncertain samples. An established tool for this are reject curves that visualize the trade-off between the number of rejected samples and classification performance metrics. We argue that common reject curves are too abstract and hard to interpret by non-experts. We propose Stacked Confusion Reject Plots (SCORE) that offer a more intuitive understanding of the used data and the classifier's behavior. We present example plots on artificial Gaussian data to document the different options of SCORE and provide the code as a Python package.
WRDScore: New Metric for Evaluation of Natural Language Generation Models
The problem of natural language generation, and, more specifically, method name prediction, faces significant difficulties when proposed models need to be evaluated on test data. Such a metric would need to consider the versatility with which a single method can be named, with respect to both semantics and syntax. Measuring the direct overlap between the predicted and reference (true) sequences will not be able to capture these subtleties. Other existing embedding based metrics either do not measure precision and recall or impose strict unrealistic assumptions on both sequences. To address these issues, we propose a new metric that, on the one hand, is very simple and lightweight, and, on the other hand, is able to calculate precision and recall without resorting to any assumptions while obtaining good performance with respect to the human judgement.