Extracting topics is a good unsupervised data-mining technique to discover the underlying relationships between texts. There are many different approaches with the most popular probably being LDA but…
J. Zevering, D. Borrmann, A. Bredenbeck, and A. Nüchter. IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS '22), page 5656--5663. Kyoto, Japan, (October 2022)