Dissertation, Otto-Friedrich-Universität Bamberg, 2026

The research field of Natural Language Processing (NLP) has experienced a major shift since the introduction of Large Language Models (LLMs). All facets and application scenarios within NLP have been impacted by the use of LLMs. Current research as well as practice of text processing tools is focused mainly on the application and development of LLMs. Major investments, not only by LLM providers but also other companies applying LLMs in their workflows, have only solidified the role of LLMs in NLP - and in other research and application areas - as part of the artificial intelligence boom in recent years.

However, limitations and downsides of the application of LLMs have also emerged. Problems regarding the generated texts as well as the environmental impact of the large-scale use of LLMs are just two of many factors that should be critically analyzed, despite the hype and the prevalence of LLMs for NLP tasks. These restrictions provide the main motivation for this thesis. Traditional models as alternatives to LLMs will be discussed from different perspectives. The characterization of traditional models will be progressively developed as features of alternatives to LLMs will emerge during the course of this thesis. This process will be grounded in experiments, observations and evaluations. Several NLP applications will be presented by surveying the state of the art with neural network-based models such as LLMs as well as the current usage of traditional models. The concrete NLP applications comprise information and relation extraction, text classification, text segmentation, text simplification and text summarization.

The first half of this thesis will present the emergence of LLMs contextualized along previous developments within NLP. Characteristics of the selected NLP applications will be collected before a structured literature review will display the prevalence of LLMs regarding each application and will discuss if traditional models are still actively researched. Lessons from domains with long-standing development procedures and processes will also be taken into account to provide a purposeful and structured manner of approaching NLP tasks. A collection of challenges within current NLP will conclude the first half of the thesis, which will serve as motivation for the analysis of experiments and applications of the latter half.

The second half of this thesis will present observations and evaluations from use cases, aligned towards the challenges recognized in the first half. Through the analysis of these use cases, benefits of applying traditional models will be collected and supported, in particular through the analysis of a text segmentation use case that is purposefully applied with the lessons drawn from the first half of the thesis in mind. The interpretation of these results will conclude in a discussion on the applicability of traditional models in contrast to LLMs and also give recommendations of both model types for different use cases.

Concrete use cases for information extraction, entity matching, text classification and text segmentation will be presented, in which traditional models match or surpass the performance of modern methods. Through improved efficiency as well as enhanced explainability and reproducibility in comparison with neural network-based techniques, these showcases demonstrate the continued relevancy of traditional techniques in today's NLP landscape.

Overall, this thesis discusses the role of traditional models in current NLP research and practice, especially in contrast and comparison to modern neural network-based approaches including LLMs. The applicability of modern and less modern techniques is analyzed through a case-based analysis of NLP tasks in a structured and purposeful manner.