Matching and Linking Entries in Historical S wedish Encyclopedias (2025)

Abstract: The Nordisk familjebok is a Swedish encyclopedia from the 19th and 20th centuries. It was written by a team of experts and aimed to be an intellectual reference, stressing precision and accuracy. This encyclopedia had four main editions remarkable by their size, ranging from 20 to 38 volumes. As a consequence, the Nordisk familjebok had a considerable influence in universities, schools, the media, and society overall. As new editions were released, the selection of entries and their content evolved, reflecting intellectual changes in Sweden.In this paper, we used digitized versions from Project Runeberg. We first resegmented the raw text into entries and matched pairs of entries between the first and second editions using semantic sentence embeddings. We then extracted the geographical entries from both editions using a transformer-based classifier and linked them to Wikidata. This enabled us to identify geographic trends and possible shifts between the first and second editions, written between 1876–1899 and 1904–1926, respectively.Interpreting the results, we observe a small but significant shift in geographic focus away from Europe and towards North America, Africa, Asia, Australia, and northern Scandinavia from the first to the second edition, confirming the influence of the First World War and the rise of new powers. The code and data are available on GitHub at https://github.com/sibbo/nordisk-familjebok.

## introduction encyclopedias are semi-structured, informationrich bodies of knowledge. in the field of knowledge extraction, their organization into articles with a headword makes them easier to process. ## previous work this work addresses three main problems: classifying entries, matching them across editions, and linking each entry to its counterpart in a knowledge graph like wikidata. we outline relevant techniques and review previous work. many of them use models trained on english. we also describe models specific to swedish. ## preprocessing project runeberg is an online archive of old scandinavian literature @xcite . this archive provides complete digital facsimiles and ocr texts of the first, second, and fourth editions of the nordisk familjebok, and parts of the third. volunteers have carried out a manual proofreading on the vast majority of the ocr texts of the first edition, and parts of the second edition, as well as creating a currently incomplete index over the entry headwords on each page. ## method figure 1 shows the processing pipeline consisting of scraping, segmenting, linking cross-references, location classification, edition linking, wikidata linking, and data visualization. we described the preprocessing modules, scraping, segmenting and linking cross-references in section 3. in this section, we describe the rest of the architecture. ## results and evaluation ## conclusion in this paper, we compared two editions of a historical swedish encyclopedia. we described the corpus collection, the segmentation of the raw text input into entries, the categorization of entries, and how we matched pairs of entries between the two editions. we finally reported how we linked geographical entries from both editions to wikidata. in the classification and matching tasks, we used transformer models with parameters pre-trained on modern swedish. a possible improvement is to fine-tune the models on older swedish texts. we could also explore alternative algorithms for matching entries, such as the hungarian algorithm @xcite . this work enabled us to identify shifts between the two editions and a few geographic trends. most notably, the second edition reflects the evolution of the geographic awareness toward a more diverse global outlook. beyond the historical events mentioned in section 6.2, there may be countless societal, cultural, political, and economic factors contributing to these changes. we hope our work will invite further investigation to provide a better un-derstanding of the context surrounding them.