Bachelor's and Master's Theses

Bachelor's and Master's theses can be written in German or, by arrangement, in English. In the Master Data Science, the thesis has to be written in English.

Valid only for the Master Data Science: Please see this page for information.


In general, we offer topics from the fields of databases, information retrieval and semantic information systems. More precisely, our topics mainly belong to one or more of the areas of searching on semistructured data, integration of heterogeneous information sources, efficiency of large-scale search engines, conversational information retrieval, natural language processing, human computer interaction, data integration, query processing, semantic web, computational argumentation (ranking, clustering, validating and extracting arguments from natural language texts), scholarly recommendation systems, domain-specific query languages and scientometrics.

The topic of a thesis determines which person supervises the thesis. The thematic focus of the advisors can be found on their personal page under Team.

If you are interested in a topic suggested by the chair or if you have your own topic suggestion for a Bachelor's or Master's thesis, please contact Prof. Dr. Ralf Schenkel. If you have already spoken with staff of the chair about a possible topic, please also include this in your email.


Please send us a list of your successfully completed modules with your request for a thesis. This overview helps us to assess which possible topic might fit your skills.

For a Bachelor's thesis, we expect that you have already successfully completed the following modules (if included in your module plan as a compulsory module) before you apply for a topic with us, as the content is very helpful for the successful completion of a Bachelor's thesis in our topics: Database Systems (Datenbanksysteme), Non-Relational Information Systems (Nichtrelationale Informationssysteme), CS-Project (Informatik-Projekt or Großes Studienprojekt), Advanced Programming (Fortgeschrittene Programmierung or Programmierung II).

For a Master's thesis, we expect you to have attended relevant Master's lectures offered by the group in the field of database systems or information retrieval. Ideally, you should also have completed your research project with the group.

Completed Bachelor's theses

[BT] Comparison of Methods for Extracting, Retrieving and Ranking Coherent Phrases in Long Posts from Debate Portals

- no abstract available -

[BT] AQUAPLANE: Argument Quality Explainer

- no abstract available -

[BT] Development of a benchmark system for RDF and Web API alignment systems

- no abstract available -

[BT] The Use of Linguistic Cues for Assigning Statements to Political Parties

Politics and Linguistics have an inextricable affinity. A wide array of evidence suggests that latent ideological nuances are ingrained within the language of political discourse. Over the last decade, uncovering and leveraging patterns in language data has become one of the most outstanding achievements of modern Data Science, which raises some noteworthy questions regarding its prospects within the political landscape.

This paper will examine how the relationship between Politics and Linguistics can be approached in Data Science. I will explore the abilities and limitations of contemporary concepts and state-of-the-art instruments in Natural Language Processing, Machine Learning, and Information Retrieval to address questions inspired by political linguistics, and, more specifically, to classify political claims in terms of their ideology with the help of political party programs in the context of an election process. The connections between Linguistics, Ideology and Data Science are interesting in their own right, but may also be of paramount importance for practical applications. Leveraging political linguistics could have profound implications for research on political behavior, and enable a more accessible way of understanding political agendas, revealing antagonistic lexical structures that arise from a set of political parties competing for attention and support in the context of an election.

[BT] Development of an interface for the realisation of explainable alignments for the FiLiPo system

Abstract: Data integration of RDF knowledge bases is an important task that plays an increasingly important role. By using many different data sources, it is possible to expand the data stock of a knowledge base or, if necessary, to correct erroneous information in the knowledge base. For this purpose, alignment systems are increasingly used, which relate the schema of one data source to that of another data source in such a way that the data can then be transferred between the data sources. One such system is FiLiPo (Finding Linkage Points). It automatically finds mappings between the schema of a local RDF knowledge base and the schema of a web API. One of the current challenges with such systems is to integrate users more into the process.  Especially when it comes to explaining to the users how and why the system made certain decisions. This bachelor thesis therefore presents a user interface for the FiLiPo alignment system that graphically presents FiLiPo's data to users. The user interface should enable users to understand, analyse and, if necessary, change or remove the alignments generated by FiLiPo.

[BT] Interactive exploration of RDF records using FCA

Abstract: Within the framework of the Semantic Web, information (knowledge) can be recorded in so-called knowledge graphs. However, these can quickly grow to an unmanageable size, so that both the content and the structure of the graph are difficult for people to comprehend. Therefore, it is necessary to find ways to create a basic understanding of the properties of knowledge graphs.

The aim of this work is to determine "knowledge about knowledge graphs" automatically by means of the mathematical model of Formal Concept Analysis (FCA) and to present it to the user. Therefore, an interactive tool was developed with which a user can perform and control the exploration of knowledge graphs.

To confirm the effectiveness of the tool, it was tested by a number of people and then evaluated. The test persons assessed the user experience and usability of the tool as predominantly positive. The aspects rated as less good offer clues for future improvements and optimisations to make the use of the tool even more attractive.

[BT] Development of a User Interface for Relation Alignment of RDF Knowledge Bases and Web APIs using the FiLiPo Framework

Abstract: In this final thesis the user interface for the FiLiPo system is presented. The development of such user interface requires a further study of problems and risks, the drafting of a concept and its implementation. One of the main goals was to develop an intuitive user interface that allows to use all the functionalities of the FiLiPo system. The thesis provides with the short introduction into schema alignment of RDF based knowledge bases and Web APIs. It also gives short information about the Angular framework that was used for the implementation. After describing the main requirements that have to be taken into consideration and giving answers on how to implement an intuitive user interface, the main concept is presented. It is based on already known solutions and examples, but still requires some creativity for the visualization of the alignment results. Then the implementation is documented. Using the Angular allows a quick integration of different components and their easy manipulation. The results of the user evaluation are presented that show if the concept and implementation were successful or not. In the end, we discuss on the further possible improvements.

[BT] Prediciting Paper Impact based on Citation Networks

 - no abstract available -

[BT] Connecting Linked Data and Web APIs using SPARQL

Abstract: Databases are used to store information and it is therefore essential that they are complete. In reality, however, databases have gaps and therefore methods must be used to supplement this missing information. Existing Linked Data systems use interfaces (SPARQL endpoints) for this purpose, which are not provided by all data providers. The common solution in practice is to provide a web API to still be able to request information. In order to be able to supplement missing information via Web APIs, a programme is implemented in this thesis that enables the connection of Linked Data systems and Web APIs. Thus, the programme ExtendedSPARQL developed in this thesis can completely answer a query to the local knowledge base by filling in missing information on-the-fly with the help of external web APIs. In doing so, the programme decides which external Web APIs are relevant for missing information and how to request the external Web APIs. It also decides how to extract the information it is looking for from Web API responses and how to add it to the results of the query. Furthermore, ExtendedSPARQL executes as few Web API requests as possible so that missing information is added with the least effort and redundant information is avoided. It is also easy to use, so that even users with only basic SPARQL knowledge can successfully perform ExtendedSPARQL queries. ExtendedSPARQL also provides a graphical user interface, which makes it even easier to use. In a subsequent evaluation, the programme proved that missing information can be successfully added using external web APIs and that redundant results rarely occur.

[BT] Appropriate Journal Search for Publications

Abstract: Researchers are normally not familiar with the thematic orientation of all journals and conferences in their field of research. As soon as researchers want to publish their work, they face the problem of finding a suitable journal or conference where they want to submit the paper. The aim of this thesis is the development of a recommender system, which can find suitable ones in respect of a given title of a publication. The system is based on data from dblp and Semantic Scholar, which contain titles of publications as well as their abstracts and keywords. Different methods for determining the similarity and relevance of papers were investigated. These include Tf/idf, BM25 and cosine similarity in conjunction with Doc2Vec. Various techniques were analysed in order to find and rank the journals and conferences associated with the corresponding papers. In addition, methods were developed to improve the results of the recommender system, such as looking at the number of citations from journals and conferences. The methods were evaluated automatically and manually. It turned out that cosine similarity with Doc2Vec did not achieve good results in contrast to the other two methods. To improve the usability of the recommender system, a visualisation in form of a web service was implemented.

[BT] A visual query language for SPARQL

Since the development of the Semantic Web by Tim Berners-Lee, more and more information is being published on the internet as Linked Open Data. These are specially designed to be analysed by machines. All elements are given unique identifiers. The elements can then be linked to each other via relations and form ever larger networks. The result is a "Giant Global Graph" in which all things of interest can be referenced. 

But while the amount of data in the SemanticWeb is constantly growing, only a few can use it. Searching for information is difficult because the user needs some prior knowledge. On the one hand, he needs to know how the data in the graph are connected and how they are labelled. On the other hand, they need knowledge about the query language SPARQL, which can be used to make queries to data sources in the Semantic Web. The visual query language developed in this work makes it easier for the user to get started and thus enables even non-experts to search the Semantic Web for information. Instead of a written query, the user graphically constructs a query from prefabricated elements. For this purpose, the Visual Query Builder programme was developed in this work, which implements such a visual query language. By specifying a schema for the respective data endpoint, the user is given the elements he can use. Thus, the user can see which elements exist at all and which attributes they have. The programme developed in this work and the underlying visual query language were then evaluated by a group of test persons. Visual Query Builder was able to prove that it enables both beginners and advanced users to successfully search a data source in the Semantic Web for desired information. In the evaluation, particular attention was paid to the usability of the application. The evaluation showed that the application achieved good results in both test procedures used and was able to prove its effectiveness.

[BT] Hybrid SPARQL queries via Linked Data and Web APIs

Digital libraries, such as dblp or the German National Library (DNB), aim to bring knowledge together online and make it available via the internet. Unfortunately, incomplete data sets are part of the everyday life of a digital library. Missing information, such as titles or author names, could be added using external web APIs. The main problem here is the integration of the external data into the local database, since a common schema, which serves to describe the structure of the data, must first be found. This is the main task of schema integration, which is a subfield of information integration and data migration. The ActiveSPARQL programme designed in this thesis exploits schema integration to use data from Web APIs to answer queries on-the-fly. When a user makes a query to the application, both the data from the local database and the externalWeb-APIs should be used to answer it satisfactorily. Using both sources is called a hybrid request. The design is based on the already existing framework ANGIE. In contrast to this, no wrapper is generated to answer the query, but an extended SPARQL query. In addition, ANGIE requires that the access methods of the web APIs must be declared manually. This step can be automated by the AID4SPARQL programme. This is able to find linkage points between the local and external data and thus ensure that external information is compatible with the local data. The results from AID4SPARQL are prepared in such a way that they can be used as a configuration for communication with web APIs. In addition to ActiveSPARQL, aWeb interface was designed to enable non-experts to create and execute hybrid queries without prior knowledge. Finally, a concept for evaluating the framework is presented, which can be used to compare ANGIE and ActiveSPARQL.

[BT] Comparison of contextualised embedding methods for similarity calculation of statements

 - no abstract available -

[BT] Feature Evaluation of Citation Distance Networks: Exploring new ways of measuring Scientific Impact

Abstract: This thesis introduces improvements to current approaches of classifying scientific work by observing the semantic similarity of publications in the same citation neighborhood. Available patterns in the neighborhood structures are used to generate an initial set of features. Different text representations, similarity measures and feature modes are implemented and studied to explore new approaches of generating meaningful features that improve classification procedures. Features are evaluated in terms of their predictive power when learning a model that distinguishes between seminal and survey publications. Learning patterns from features to better distinguish between the publications will be a proxy of the effectiveness of these features in evaluating research impact. The state-of-the-art research in this area achieved a result of 68.97% prediction accuracy whereas the approaches presented in this thesis achieved a prediction accuracy of up to 86.98% and therefore beat the latest results by a large margin. Thorough evaluation of the feature sets reveals which relationships in a neighborhood structure provide information that can help improve current research evaluation metrics by identifying high impact scientific work.

Keywords: Semantometrics - Feature Engineering - Natural Language Processing

[BT] Learning the Interface of Web APIs

All kinds of information can be retrieved from web APIs, for example metadata of publications. However, it is not always obvious what kind of data must be sent to the web API in order to receive a meaningful response. For this problem, a programme was developed that learns the appropriate transfer parameters of web APIs with the help of a source database. For this purpose, each type of data from the source database is sent to the web API and it is checked whether the response of the API is related to the sent data. Various parameters can be used to configure how closely the responses of the web API must match the data of the source database in order to be considered meaningful. For this purpose, several metrics for calculating string similarities were used to find the matches of both data sets. Through a suitable evaluation, it could be shown that with good configuration parameters all matches are found. In the presented system, a user also has the possibility to choose different metrics to compare the similarity of two values. For example, it is possible to specify that there must be an exact match between some data, such as ISBNs or other IDs. With the right configuration parameters, as well as knowing and specifying which metric is best for which type of data, almost any data can be recognised as a match that a human would also consider a match.

[BT] Resolver for conference venues

 - no abstract available -

[BT] Development of a Web-Based Time Clock System with Additional Project Tracking Functionality

 - no abstract available -

[BT] Meter reading app

 - no abstract available -

[BT] Development of a procedure for the automatic matching of bibliographic databases

 - no abstract available -

[BT] Development of a crawler for comments in online media

 - no abstract available -

[BT] Similarity measures for the literature database DBLP

 - no abstract available -

[BT] Development of a procedure for the automatic matching and merging of institute records

 - no abstract available -

[BT] Design and implementation of a search engine for a web archive

 - no abstract available -

[BT] Development of a browser extension to build a personal web archive

 - no abstract available -

Completed Master's theses

[MT] Reconstruction of Argumentation Graphs

Argumentation can be understood as the activity of using arguments to convince, agree, or disagree people with people about a point of view. In our daily lives, argumentation is one of the most common behaviors in applying natural language. For example, social media users would respond to controversial topics using their stances and opinions. The collection and analysis of user ideas are critical to studying social phenomena and trends. However, it is hard to analyze all collected arguments since processing enormous data size needs much time and human costs, which is undesirable. This requires more efficient methods. A possible solution might be the research in computational argumentation because computers can handle numerous data efficiently. Besides social phenomenon analysis, other areas such as business and linguistics also benefit from studying argumentation.

Computational argumentation is a growing research field that yield many new methods in this area. This work is inspired by a study investigating in transforming natural language texts to argument graphs. In this thesis, we base on the previous studies and explore deep into the steps of each part, including classifying major claims, inferring relations between statements, and constructing argument graphs, and investigate in approaches for improvement. We propose a new method in major claim classification, which is to find the statement describing the core idea of the discussion, and obtain an excellent enhancement. Moreover, we introduce state-of-the-art methods to estimate the relations between arguments. We suggest six methods in the step of argument graph construction, which also give satisfactory results. There are some limitations to our research. We discuss them and explore some possible further improvements for achieving a better result in the future studies.

[MT] Fine-tuning a Transformer model for Multilingual document semantic similarity

An information retrieval system’s purpose is to return results that are relevant to the user’s query. Information relevant to the user’s request may not exist in the user’s native language in some instances. It’s also possible that the user can read papers in languages other than his or her native tongue but has trouble forming inquiries in them. The primary goal of Multilingual Information Extraction is to locate the most relevant information accessible, regardless of the query language.

Artificial intelligence (AI) has become an increasingly popular research field in recent years. Similarly, Natural Language Processing (NLP) has become an important point of discussion. Neural networks, do exceptionally well in this field. The speed and performance of neural networks dealing with diverse NLP tasks have been greatly enhanced due to a variety of effective learning methods and technologies.

The recent advances in NLP transfer learning have resulted in powerful models, mostly from the tech giants like Google, Facebook, Microsoft, etc. which perform well on NLP tasks in the general domain. In this thesis, we are going to fine-tune multilingual transformer models for the domain of engineering data both in English and German Languages. Hence, we need a language independent model - which can able to learn it’s parameters (weights and bias) of any language-specific features. First, we will describe how multilingual transfer is implemented, with the focus on state-of-the-art transformer models. Then, in the methodology part, we leverage our engineering domain data of English-German languages to fine-tune multilingual transformer models.

[MT] Towards (semi) automated literature-based complete transformer-based MCQ generation model for data base related field deployment

- no abstract available -

[MT] Creating and implementing a pipeline for retrieving and ranking arguments by relevance and quality for controversial questions

Abstract: Argumentation is considered to be a foundational discipline. Initially, its objectives are to foster critical thinking and logical reasoning, to reach a resolution when people disagree, persuade or convince others of a particular viewpoint or position, and also can be a tool for knowledge exchange.

Individuals can explore arguments that either support or attack their own opinions, leveraging their personal knowledge and life experiences, but they also can use search engines (e.g., Google) accessed by the Internet. In this work, we focus on the arguments taken from the Web. The user could ask (input the query) the search engine a particular question, e.g., “Should I own a dog?” and will expect to receive an answer in the form of a list of Web pages (sorting by relevance), textual information, images, videos, news articles, and social media’s posts.

Usually, arguments for a specific question are in the text, which is a part of the Web page (also called “document”). The document may contain argumentative and non-argumentative text spans. The aim is to retrieve the documents, such that their argumentative parts are relevant to the query and highly qualified (argumentative). However, there is the issue that the retrieved documents may consist of arguments with low relevance to the query, low quality, or falsified, and there is usually no clear stance. Therefore, these documents will not satisfy the user’s expectations, or the user will use the wrong, fake, biased arguments to support the position.

The problem with search engines like Google is that users looking for reasonable arguments within a short time are required to do a significant amount of work after submitting their query. This work includes tasks such as reading pages, identifying arguments, filtering duplicates, and manually ranking them. In contrast, argument search engines aim to alleviate this burden by handling these tasks for users and presenting them with the best arguments. This proves advantageous in debates, interviews, and political discussions, as it ensures the availability of the strongest arguments for making informed decisions.

Our work was inspired by the Touché Lab Task 1 named “Argument Retrieval for Controversial Questions”, whose objective is to retrieve and rank documents by relevance to the topic, by argumentativeness of the documents (quality), and to detect their stance towards the topic. In this work, we investigate various methods and techniques for argument mining (i.e., automatic extraction of arguments from the document) and preprocessing for the purpose of working with individual arguments from the document rather than the entire text as a whole. We applied stance classification (i.e., determining whether the premise supports or attacks the specific claim) and quality prediction to get high-quality arguments 1 . To expand the search for the re-ranking model, we utilize query augmentation, which is performed with the assistance of ChatGPT. The primary objective is to optimally combine these approaches to retrieve highly relevant results with high-quality arguments and demonstrate that working with individual arguments produces better results than working with the entire text.

For our experiments and evaluation, we utilize several datasets and resources. The “ClueWeb22-B” corpus and controversial questions provided by the Touch´e Lab served as the basis for our analysis. The SNLI dataset is utilized to establish relations between claims and premises. At the same time, the “” dataset is explicitly employed for stance classification. To predict the argument’s quality, we rely on the “Webis-ArgQuality-20” and “IBM-ArgQ-Rank-30kArgs” datasets.

To evaluate the effectiveness of our approach, we compare our results with the baseline of Touché Task 1. To ensure fair comparisons, we utilize manually annotated judgments as a benchmark for both our results and the baselines. Our approach demonstrates superior performance in the nDCG measurement compared to the baseline of Touché Lab Task 1 and achieves an accuracy of 0.54 for stance classification. It highlights the effectiveness and competitiveness of our approach in retrieving and ranking relevant arguments by relevance and quality, as well as classifying them by stance.

[MT] Automatic Fake News Detection on Tweets

 - no abstract available -