Regression
Annotate Rhetorical Relations with INCEpTION: A Comparison with Automatic Approaches
Automatically identifying rhetorical relations in discourse units is a challenging task in natural language processing (NLP) because it should be able to logically and semantically connect the discourse units. Although large language models (LLMs) shows po tential for application in many domains, including text classification tasks, their effectiveness in predicting rhetorical relations remains open for research. One of the major challenges in this domain is the lack of annotated data sets capturing differen t rhetorical relations, which would then make model training more difficult. In this research, we manually created the da-tasets from various cricket reports and then annotated the reports as discourse units. We used the INCEpTION annotation tools for annotation and then structured the dataset for the machine - learning model.
From Theory to Practice: Evaluating Data Poisoning Attacks and Defenses in In-Context Learning on Social Media Health Discourse
Jhuma, Rabeya Amin, Faisal, Mostafa Mohaimen Akand
This study explored how in-context learning (ICL) in large language models can be disrupted by data poisoning attacks in the setting of public health sentiment analysis. Using tweets of Human Metapneumovirus (HMPV), small adversarial perturbations such as synonym replacement, negation insertion, and randomized perturbation were introduced into the support examples. Even these minor manipulations caused major disruptions, with sentiment labels flipping in up to 67% of cases. To address this, a Spectral Signature Defense was applied, which filtered out poisoned examples while keeping the data's meaning and sentiment intact. After defense, ICL accuracy remained steady at around 46.7%, and logistic regression validation reached 100% accuracy, showing that the defense successfully preserved the dataset's integrity. Overall, the findings extend prior theoretical studies of ICL poisoning to a practical, high-stakes setting in public health discourse analysis, highlighting both the risks and potential defenses for robust LLM deployment. This study also highlights the fragility of ICL under attack and the value of spectral defenses in making AI systems more reliable for health-related social media monitoring.
Total Robustness in Bayesian Nonlinear Regression for Measurement Error Problems under Model Misspecification
Chen, Mengqi, Dellaporta, Charita, Berrett, Thomas B., Damoulas, Theodoros
Modern regression analyses are often undermined by covariate measurement error, misspecification of the regression model, and misspecification of the measurement error distribution. We present, to the best of our knowledge, the first Bayesian nonparametric framework targeting total robustness that tackles all three challenges in general nonlinear regression. The framework assigns a Dirichlet process prior to the latent co-variate-response distribution and updates it with posterior pseudo-samples of the latent covariates, thereby providing the Dirichlet process posterior with observation-informed latent inputs and yielding estimators that minimise the discrepancy between Dirichlet process realisations and the model-induced joint law. This design allows practitioners to (i) encode prior beliefs, (ii) choose between pseudo-sampling latent covariates or working directly with error-prone observations, and (iii) tune the influence of prior and data. We establish generalisation bounds that tighten whenever the prior or pseudo-sample generator aligns with the underlying data generating process, ensuring robustness without sacrificing consistency. A gradient-based algorithm enables efficient computations; simulations and two real-world studies show lower estimation error and reduced estimation sensitivity to misspecification compared to Bayesian and frequentist competitors. The framework, therefore, offers a practical and interpretable paradigm for trustworthy regression when data and models are jointly imperfect.
Adaptive randomized pivoting and volume sampling
Adaptive randomized pivoting (ARP) is a recently proposed and highly effective algorithm for column subset selection. This paper reinterprets the ARP algorithm by drawing connections to the volume sampling distribution and active learning algorithms for linear regression. As consequences, this paper presents new analysis for the ARP algorithm and faster implementations using rejection sampling.
A Stability-based Validation Procedure for Differentially Private Machine Learning
Kamalika Chaudhuri, Staal A. Vinterbo
Differential privacy is a cryptographically motivated definition of privacy which has gained considerable attention in the algorithms, machine-learning and data-mining communities. While there has been an explosion of work on differentially private machine learning algorithms, a major barrier to achieving end-to-end differential privacy in practical machine learning applications is the lack of an effective procedure for differentially private parameter tuning, or, determining the parameter value, such as a bin size in a histogram, or a regularization parameter, that is suitable for a particular application. In this paper, we introduce a generic validation procedure for differentially private machine learning algorithms that apply when a certain stability condition holds on the training algorithm and the validation performance metric. The training data size and the privacy budget used for training in our procedure is independent of the number of parameter values searched over. We apply our generic procedure to two fundamental tasks in statistics and machine-learning - training a regularized linear classifier and building a histogram density estimator that result in end-to-end differentially private solutions for these problems.
Sense and Sensitivity Analysis: Simple Post-Hoc Analysis of Bias Due to Unobserved Confounding Victor V eitch
It is a truth universally acknowledged that an observed association without known mechanism must be in want of a causal estimate. However, Causal estimates from observational data will be biased in the presence of'unobserved confounding'. Nevertheless, we might hope that the influence of unobserved confounders is weak relative to a'large' estimated effect. The purpose of this paper is to develop Austen plots, a sensitivity analysis tool to aid such judgments by making it easier to reason about potential bias induced by unobserved confounding. We formalize confounding strength in terms of how strongly the unobserved confounding influences treatment assignment and outcome. For a target level of bias, an Austen plot shows the minimum values of treatment and outcome influence required to induce that level of bias. Austen plots generalize the classic sensitivity analysis approach of Imbens [Imb03]. Critically, Austen plots allow any approach for modeling the observed data. We illustrate the tool by assessing biases for several real causal inference problems, using a variety of machine learning approaches for the initial data analysis.
28fc2782ea7ef51c1104ccf7b9bea13d-Reviews.html
First provide a summary of the paper, and then address the following criteria: Quality, clarity, originality and significance. The paper describes a method for local bandwidth selection in kernel regression models, which ensures adaptivity to local smoothness and dimension. Quality: The paper presents a useful result for adaptivity in kernel regression. The work is set out well. I think that it would be useful to have some more discussion of the bandwidth selection procedure.
7a006957be65e608e863301eb98e1808-Supplemental.pdf
In Appendix A, we review some statistical results for sparse linear regression. In Appendix B, we provide the proof of main theorems as well as main claims. We review some classical results in sparse linear regression. B.1 Proof of Claim 3.5 We first prove the first part. Combining with Eq. (B.6), we have under event D B.2 Proof of Claim 3.6 From the divergence decomposition lemma (Lemma C.2 in the appendix), we have KLnull P To prove the claim, we use a simple argument "minimum is always smaller than the average".