Building Contextual Knowledge Graphs for Personalized Learning Recommendations using Text Mining and Semantic Graph Completion
Hasan Abu-Rasheed, Mareike Dornhöfer, Christian Weber, Gábor Kismihók, Ulrike Buchmann, Madjid Fathi
TL;DR
The paper addresses the need for context-aware personalization in learning platforms by transforming hierarchical learning-object models into contextual knowledge graphs through a custom text-mining pipeline that extracts semantic relations from bilingual LO descriptions. The authors introduce a 5-level taxonomy and extend it with semantic edges, enabling LO connections across learning scenarios to support contextual recommendations. They validate the approach with a combination of quantitative graph-quality metrics and qualitative expert evaluations, showing increased LO connectivity, more distinct contextual communities, and higher betweenness centrality compared to the original hierarchy. The work demonstrates that semantic KG completion can robustly represent LO context, though it relies on rich textual metadata and faces multilingual challenges, suggesting directions for improving robustness and domain-specific feature integration.
Abstract
Modelling learning objects (LO) within their context enables the learner to advance from a basic, remembering-level, learning objective to a higher-order one, i.e., a level with an application- and analysis objective. While hierarchical data models are commonly used in digital learning platforms, using graph-based models enables representing the context of LOs in those platforms. This leads to a foundation for personalized recommendations of learning paths. In this paper, the transformation of hierarchical data models into knowledge graph (KG) models of LOs using text mining is introduced and evaluated. We utilize custom text mining pipelines to mine semantic relations between elements of an expert-curated hierarchical model. We evaluate the KG structure and relation extraction using graph quality-control metrics and the comparison of algorithmic semantic-similarities to expert-defined ones. The results show that the relations in the KG are semantically comparable to those defined by domain experts, and that the proposed KG improves representing and linking the contexts of LOs through increasing graph communities and betweenness centrality.
