Ensuring the safety of Large Language Models (LLMs) is a critical alignment challenge. Existing approaches often rely on invasive fine- tuning or external generation-based checks, which can be opaque and resource-inefficient. In this work, we investigate the geometry of safety concepts within pretrained representations, proposing a mechanistic methodology that identifies the layer where safe and unsafe concepts are maximally separable within a pretrained model’s representation space. By leveraging the intrinsic activation space of the optimal layer, we show that safety enforcement can be achieved via a simple linear classifier, avoiding the need for weight modification. We validate our framework across multiple domains (regulation, law, finance, cybersecurity, education, code, human resources, and social media), diverse tasks (safety classification, prompt injection, and toxicity detection), and 16 non-English languages on both encoder and decoder architectures. Our results show that: (i) the separation between safe and unsafe concepts emerges from a single layer direction in the activation space, (ii) monitoring internal representations provides a significantly more robust safeguarding mechanism compared to traditional evaluative or generative guardrail paradigms.

In a rapidly evolving labor market, detecting and addressing emerging skill needs is essential for shaping responsive education and workforce policies. Online job advertisements (OJAs) provide a real-time view of changing demands, but require first retrieving skill mentions from unstructured text and then solving the entity linking problem of connecting them to standardized skill taxonomies. To harness this potential, we present a multilingual human-in-the-loop (HITL) pipeline that operates in two steps: candidate skills are extracted from national OJA corpora using country-specific word embeddings, capturing terms that reflect each country’s labor market. These candidates are linked to ESCO using an encoder-based system and refined through a decoder large language models (LLMs) for accurate contextual alignment. Our approach is validated through both quantitative and qualitative evaluations, demonstrating that our method enables timely, multilingual monitoring of emerging skills, supporting agile policy-making and targeted training initiatives.

Enriching sentences with knowledge from qualitative sources benefits various NLP tasks and enhances the use of labeled data in model training. This is crucial for Financial Sentiment Analysis (FSA), where texts are often brief and contain implied information. We introduce RE-FIN (Retrieval-based Enrichment for FINancial data), an automated system designed to retrieve information from a knowledge base to enrich financial sentences, making them more knowledge-dense and explicit. RE-FIN generates propositions from the knowledge base and employs Retrieval-Augmented Generation (RAG) to augment the original text with relevant information. A large language model (LLM) rewrites the original sentence, incorporating this data. Since the LLM does not create new content, the risk of hallucinations is significantly reduced. The LLM generates multiple new sentences using different relevant information from the knowledge base; we developed an algorithm to select one that best preserves the meaning of the original sentence while avoiding excessive syntactic similarity. Results show that enhanced sentences present lower perplexity than the original ones and improve performances on FSA.

Recent advancements in Large Language Models (LLMs) have been reshaping Natural Language Processing (NLP) task in several domains. Their use in the field of Human Resources (HR) has still room for expansions and could be beneficial for several time consuming tasks. Examples such as time-off submissions, medical claims filing, and access requests are noteworthy, but they are by no means the sole instances. However the aforementioned developments must grapple with the pivotal challenge of constructing a high-quality training dataset. On one hand, most conversation datasets are solving problems for customers not employees. On the other hand, gathering conversations with HR could raise privacy concerns. To solve it, we introduce HR-Multiwoz, a fully-labeled dataset of 550 conversations spanning 10 HR domains. Our work has the following contributions:(1) It is the first labeled open-sourced conversation dataset in the HR domain for NLP research. (2) It provides a detailed recipe for the data generation procedure along with data analysis and human evaluations. The data generation pipeline is transferrable and can be easily adapted for labeled conversation data generation in other domains. (3) The proposed data-collection pipeline is mostly based on LLMs with minimal human involvement for annotation, which is time and cost-efficient.

The recent growth of black-box machine-learning methods in data analysis has increased the demand for explanation methods and tools to understand their behaviour and assist human-ML model cooperation. In this paper, we demonstrate ContrXT, a novel approach that uses natural language explanations to help users to comprehend how a back-box model works. ContrXT provides time contrastive (t-contrast) explanations by computing the differences in the classification logic of two different trained models and then reasoning on their symbolic representations through Binary Decision Diagrams. ContrXT is publicly available at ContrXT.ai as a python pip package.

The recent dominance of machine learning-based natural language processing methods has fostered the culture of overemphasizing model accuracies rather than studying the reasons behind their errors. Interpretability, however, is a critical requirement for many downstream AI and NLP applications, e.g., in finance, healthcare, and autonomous driving. This study, instead of proposing any “new model”, investigates the error patterns of some widely acknowledged sentiment analysis methods in the finance domain. We discover that (1) those methods belonging to the same clusters are prone to similar error patterns, and (2) there are six types of linguistic features that are pervasive in the common errors. These findings provide important clues and practical considerations for improving sentiment analysis models for financial applications.