VLDB 2026 Research / reviewers in the wild / expert
Lorenz Sparrenberg
dblp:397/6698
· DBLP profile ↗
13ranked-venue papers in the field
3as first author
13since 2021 · last 2026
0000-0001-9450-7387ORCID · verified
Domains — venue-derived; a paper can count in several
Big Data, Cloud & Distributed Data Systems · 7 (2 first)Data Mining & Knowledge Discovery · 5 (1 first)Information Retrieval & Web Search · 1
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | Towards Reliable Machine Translation: Scaling LLMs for Critical Error Detection and Safety
Muskaan Chopra, Lorenz Sparrenberg, Rafet Sifa |
ECIR (3) | 2 |
| 2025 | From Retinal Pixels to Patients: Evolution of Deep Learning Research in Diabetic Retinopathy Screening
Muskaan Chopra, Lorenz Sparrenberg, Armin Berger, Sarthak Khanna, Jan H. Terheyden, Rafet Sifa |
IEEE Big Data | 2 |
| 2025 | How Small Can You Go? Compact Language Models for On-Device Critical Error Detection in Machine Translation
Muskaan Chopra, Lorenz Sparrenberg, Sarthak Khanna, Rafet Sifa |
IEEE Big Data | 2 |
| 2025 | Towards Uncertainty-Aware Low-Bit Quantized LLMs for On-Device Inferenceabstract5930 Lorenz Sparrenberg, Tobias Deußer, Armin Berger, Rafet Sifa |
IEEE Big Data | 1 |
| 2025 | Reasoning LLMs in the Medical Domain: A Literature SurveyabstractThe emergence of advanced reasoning capabilities in Large Language Models (LLMs) marks a transformative development in healthcare applications. Beyond merely expanding functional capabilities, these reasoning mechanisms enhance decision transparency and explainability-critical requirements in medical contexts. This survey examines the transformation of medical LLMs from basic information retrieval tools to sophisticated clinical reasoning systems capable of supporting complex healthcare decisions. We provide a thorough analysis of the enabling technological foundations, with a particular focus on specialized prompting techniques like Chain-of-Thought and recent breakthroughs in Reinforcement Learning exemplified by DeepSeek-R1. Our investigation evaluates purpose-built medical frameworks while also examining emerging paradigms such as multi-agent collaborative systems and innovative prompting architectures. The survey critically assesses current evaluation methodologies for medical validation and addresses persistent challenges in field interpretation limitations, bias mitigation strategies, patient safety frameworks, and integration of multimodal clinical data. Through this survey, we seek to establish a roadmap for developing reliable LLMs that can serve as effective partners in clinical practice and medical research. Armin Berger, Sarthak Khanna, Lorenz Sparrenberg, Tobias Deußer, David Berghaus, Rafet Sifa |
DSAA | 3 |
| 2025 | A Survey on Current Trends and Recent Advances in Text AnonymizationabstractThe proliferation of textual data containing sensitive personal information across various domains requires robust anonymization techniques to protect privacy and comply with regulations, while preserving data usability for diverse and crucial downstream tasks. This survey provides a comprehen-sive overview of current trends and recent advances in text anonymization techniques. We begin by discussing foundational approaches, primarily centered on Named Entity Recognition, before examining the transformative impact of Large Language Models, detailing their dual role as sophisticated anonymizers and potent de-anonymization threats. The survey further ex-plores domain-specific challenges and tailored solutions in critical sectors such as healthcare, law, finance, and education. We investigate advanced methodologies incorporating formal privacy models and risk-aware frameworks, and address the specialized subfield of authorship anonymization. Additionally, we review evaluation frameworks, comprehensive metrics, benchmarks, and practical toolkits for real-world deployment of anonymization solutions. This review consolidates current knowledge, identifies emerging trends and persistent challenges, including the evolving privacy-utility trade-off, the need to address quasi-identifiers, and the implications of LLM capabilities, and aims to guide future research directions for both academics and practitioners in this field. Tobias Deußer, Lorenz Sparrenberg, Armin Berger, Max Hahnbück, Christian Bauckhage, Rafet Sifa |
DSAA | 2 |
| 2025 | Towards Unified Multimodal Financial Forecasting: Integrating Sentiment Embeddings and Market Indicators via Cross-Modal AttentionabstractWe propose STONK (Stock Optimization using News Knowledge), a multimodal framework integrating numerical market indicators with sentiment-enriched news embeddings to improve daily stock-movement prediction. By combining numerical & textual embeddings via feature concatenation and cross-modal attention, our unified pipeline addresses limitations of isolated analyses. Backtesting shows STONK outperforms numeric-only baselines. A comprehensive evaluation of fusion strategies and model configurations offers evidence-based guidance for scalable multimodal financial forecasting. Source code is available on GitHub11https://github.com/sarthak-12/thesis-dsaa/. Sarthak Khanna, Armin Berger, David Berghaus, Tobias Deußer, Lorenz Sparrenberg, Rafet Sifa |
DSAA | 5 |
| 2025 | Predicting Player Churn with LLMs: A Comprehensive Evaluation of World Knowledge and ReasoningabstractWhile large language models (LLMs) have demonstrated impressive results on public benchmarks, their effectiveness in structured, real-world problems like behavioral analytics remains underexplored. This work assesses the out-of-the-box performance of LLMs for industry-specific downstream tasks, with player churn prediction as a representative task. Evaluating LLMs on public benchmarks risks data leakage and task-specific overfitting, so instead we perform experiments on a novel self-compiled dataset for churn prediction, a task not part of any standard benchmark. We compare the performance of OpenAI's GPT-4.1 with traditional machine learning models, such as XGBoost and MLPs, and analyze the impact of the LLM's extensive internal world knowledge and reasoning capabilities. With few-shot prompting, GPT-4.1 achieves a weighted F1 score of 0.787, matching the performance of XGBoost on the same set of samples. We show that the LLM can compensate for missing information with its internal world knowledge and reasoning capabilities, performing best if it can leverage both. Our results highlight the potential of LLMs for cross-game churn prediction and other structured, industry-specific tasks. Lorenz Sparrenberg, Rafet Sifa |
DSAA | 2 |
| 2025 | Small and Fast LLMs on Commodity Hardware: Post-Training Quantization in llama. cppabstractLarge Language Models (LLMs) have demonstrated remarkable capabilities but their significant computational and memory demands hinder widespread deployment, especially on resource-constrained devices. Quantization, the process of reducing the numerical precision of model parameters, has emerged as a critical technique for compressing LLMs and accelerating inference. This paper provides an overview of LLM quantization, with a particular focus on the Post-Training Quantization (PTQ) methods implemented within the popular llama. cpp framework and its GGUF file format. We begin by covering quantization fundamentals, including the distinction between PTQ and Quantization-Aware Training (QAT). We then describe the specific PTQ schemes employed by llama. cpp, including legacy methods, advanced K-quants, and recent IQ-quants, along with their underlying mathematical principles. The paper also discusses the impact of these techniques on model fidelity, hardware requirements, inference speed, and traces the adoption of GGUF as a de facto standard in the open-source community. This work serves as a practical guide and comprehensive reference for researchers aiming to deploy LLMs on resource-constrained hardware. By systematically documenting and comparing the PTQ methods within llama. cpp, we provide the necessary insights to navigate the trade-offs between model fidelity, inference speed, and memory footprint. This enables informed decision-making for real-world applications, from local CPU-based inference to efficient edge deployment. Lorenz Sparrenberg, Tobias Deußer, Armin Berger, Rafet Sifa |
DSAA | 1 |
| 2024 | Fusing Speech and Language Models for Dementia DetectionabstractAccurate detection of dementia is crucial for timely intervention and care, and leveraging multimodal data holds significant potential for improving diagnostic accuracy. In this study, we explore deep learning approaches for dementia classification using the Pitt corpus, which includes brief participant descriptions of a cookie theft scene. We analyze 242 control and 307 dementia audio clips to investigate various representation learning techniques. Our best-performing approach fuses audio spectrograms with advanced language models, including Whisper model transcriptions and transformer-based feature extraction. We rigorously evaluate these models and find that our multimodal approach with an F1-score of 86.42% eclipses other single modality approaches by a considerable margin. Our findings underscore the promise of multimodal deep learning techniques in advancing the reliability of dementia detection through audio analysis, possibly paving the way for more robust and accessible diagnostic tools. Tobias Deußer, Abdul Mohsin Siddiqi, Lorenz Sparrenberg, Tobias Adams, Christian Bauckhage, Rafet Sifa |
IEEE Big Data | 3 |
| 2024 | A Comparative Study of Large Language Models for Named Entity Recognition in the Legal DomainabstractNamed Entity Recognition (NER) in the legal domain presents unique challenges due to specialized terminology and complex linguistic structures inherent in legal texts. While large language models (LLMs) like GPT-4, Llama-3, and others have significantly advanced natural language processing, their effectiveness in domain-specific tasks like legal Named Entity Recognition remains underexplored. This study conducts a comprehensive comparative analysis of eleven state-of-the-art LLMs on legal NER tasks across seven diverse datasets in five languages, namely English, Portuguese, German, Turkish, and Ukrainian. We evaluate the models’ performance using F1scores, focusing on their ability to accurately identify and classify legal entities. Our findings reveal significant variability in LLM performance across different languages and legal contexts, with proprietary models like GPT-4 achieving the highest overall scores. The results highlight the influence of model architecture, dataset characteristics, and prompt design on the effectiveness of legal NER tasks. This study provides valuable benchmarks for legal NER applications and offers insights into the strengths and limitations of current LLMs, guiding future research and development in legal natural language processing. Tobias Deußer, Lorenz Sparrenberg, Daniel Uedelhoven, Armin Berger, Maren Pielka, Lars Patrick Hillebrand, Christian Bauckhage, Rafet Sifa |
IEEE Big Data | 3 |
| 2024 | Leveraging Large Language Models for Few-Shot KPI Extraction from Financial ReportsabstractWe explore the use of Large Language Models (LLMs) for automating the extraction of Key Performance Indicators (KPIs) from diverse financial reports without any additional fine-tuning. We focus on evaluating various proprietary and open-source LLMs to address the joint named entity recognition and relation extraction tasks essential for accurately linking KPIs to their corresponding values and attributes. Our study highlights the technical challenges involved in the extraction process and presents a comprehensive evaluation of the models’ effectiveness. Our results reveal significant insights into handling these LLMs in such a crucial environment and showcase the transformative potential of LLMs in enhancing financial analysis and decision-making. Tobias Deußer, Daniel Uedelhoven, Lorenz Sparrenberg, Lars Patrick Hillebrand, Christian Bauckhage, Rafet Sifa |
IEEE Big Data | 4 |
| 2024 | Correcting Systematic Bias in LLM-Generated Dialogues Using Big Five Personality TraitsabstractThe ability of large language models (LLMs) to simulate human behavior and psychological traits holds significant promise for applications in psychology and the social sciences. This paper investigates the feasibility of generating synthetic dialogue datasets that accurately reflect real-world distributions of personality traits, based on the Big Five personality model. Using GPT-4o-mini, we prompt the model with personality traits that mirror population-level distributions to generate dialogues. However, systematic deviations, particularly in the representation of extreme personality traits, are observed — likely due to biases introduced during LLM training and alignment. To address these deviations, we propose a rescaling method that corrects the initial personality traits used for prompting the LLM, ensuring that the generated dialogues more closely match the expected distributions. This correction enhances the quality and reliability of the synthetic dialogues, paving the way for more effective use of LLMs in psychological research and social science applications. Lorenz Sparrenberg, Tobias Deußer, Markus Koppenborg, Rafet Sifa |
IEEE Big Data | 1 |